The Flight and Demise of Icarus.

A sequence of David Sycamore.
Written by Michael Thomas De Vlieger, St. Louis, Missouri, 2021 0304.

Abstract.

We examine a nested doubly conditional self-referential sequence with contramanding counting functions that produces two major canonical nontrivial trajectories and 76 departures from such. We study the effect of the initial term x, considered a seed, as well as explore the tree of possible trajectories.

Introduction.

This paper describes a doubly conditional self-referential recursive mapping h(x), where x ≥ 0 is an integer used as a seed. The recursive mapping of h(x) produces an infinite sequence, however, there is a mechanism that eventually arises given any x that results in a fixed point of 0.

The map h(x) produces a sequence beginning with sx(0) = x, incrementing thereafter n times. We subject the term x to Condition A, a novelty test, and in both outcomes, to Condition B, a primality test, yielding output based on the four possible overlaid conditions. The output serves as input for another mapping until we encounter two adjacent zeros (a fixed point of 0). We say a number m is novel if it does not already appear in s, and extant if it already appears at least once at s(k) for k < n.

Therefore, we define a sequence sx starting with sx(0) = x.
For novel prime s(n), we report the number c of primes m in s at s(n+1).
For novel nonprime s(n), we report the number (nc) of nonprimes m in s at s(n+1).
For extant prime s(n) whose penultimate index is k, we write at s(n+1) the number of nonprimes in s(j), k < j < n.
For extant nonprime s(n) whose penultimate index is k, we write at s(n+1) the number of primes in s(j), k < j < n.

Conditional structure of s.

There are 4 practical conditions, to which we assign labels.

We use these conditions to produce an auxiliary sequence r that tracks the condition enacted during each iteration.

The general effect of Conditions 0 and 1 (the novel conditions) is to introduce the status of c or (nc) at s(n+1) if and only if m is novel. Since there are more nonprimes than primes in the intervals dealt with during generation, the trajectory of (nc) proves higher and more continuous than that of c in the scatterplot of s. Each time Condition 0 or 1 occurs, the respective counting function has strictly increased. Therefore, generally, the emergence of these conditions has a sustaining effect upon the duration of a nontrivial run of s. Using the analogy of Icarus, these two conditions perhaps represent his flight, maybe a bit too close to the sun.

The general effect of Conditions 2 and 3 (the extant conditions) is to report the number of integers in the interval between the latest 2 instances of m with opposite primality at s(n+1). Hence, Condition 3 (pertaining to extant primes) tends to report larger numbers of nonprimes more infrequently than Condition 2 reports smaller numbers of primes. Condition 2 tends to be the reason that forces s into a fixed point through instigating 2 adjacent zeros. Again, the analogy of Icarus has us consider these conditions as Icarus’ fateful accumulation of sea-spray until he crashes into the Aegean.

Generation of sequence s.

We now examine three examples of the recursive mappings of h(x) given seeds 1, 2, and 12.

s1 begins:

1, 1, 0, 3, 1, 1, 0, 1, 0, 0, ...

s1(1) = 1 since s1(0) is a novel nonprime, and there is 1 nonprime in the sequence.
s1(2) = 0 since s1(1) is a nonprime that appeared at s1(0); between s1(0) and s1(1) there are no primes.
s1(3) = 3 since s1(2) is a novel nonprime, and there are 3 nonprimes in the sequence.
s1(4) = 1 since s1(3) is a novel prime, and there is 1 prime in the sequence.
s1(5) = 1 since s1(4) is a nonprime that appeared at s1(1); between s1(1) and s1(4) there is 1 prime.
s1(6) = 0 since s1(5) is a nonprime that appeared at s1(4); between s1(4) and s1(5) there are no primes.
s1(7) = 1 since s1(6) is a nonprime that appeared at s1(2); between s1(2) and s1(6) there is 1 prime.
s1(8) = 0 since s1(7) is a nonprime that appeared at s1(5); between s1(5) and s1(7) there are no primes.
s1(9) = 0 since s1(8) is a nonprime that appeared at s1(6); between s1(6) and s1(8) there are no primes.

For n > 9, we will always have 0 since there are no primes between adjacent zeros, and the sequence is hereinafter trivial. Hence, we may speak of a nontrivial run length , the number of iterations necessary to produce 2 adjacent zeros. Therefore, 1 = 8.

s2 begins:

2, 1, 1, 0, 3, 2, 3, 0, 3, 1, 4, 6, 7, 6, 1, 1, 0, 2, 8, 12, 13, 8, 1, 2, 4, 4, 0, 3, 14, 19, 11, 12, 5, 13, 7, 13, 0, 7, 1, 9, 23, 18, 24, 25, 26, 27, 28, 29, 19, 10, 30, 31, 21, 32, 33, 34, 35, 36, 37, 22, 38, 39, 40, 41, 23, 18, 6, 18, 0, 8, 16, 47, 25, 7, 27, 8, 2, 35, 6, 3, 34, 7, 5, 33, 9, 13, 35, 4, 22, 9, 1, 14, 21, 10, 11, 44, 64, 65, 66, 67, 33, 3, 16, 10, 3, 2, 20, 71, 37, 34, 10, 4, 7, 21, 8, 13, 21, 1, 9, 9, 0, 16, 6, 13, 7, 9, 2, 14, 12, 31, 55, 87, 88, 89, 45, 90, 91, 92, 93, 94, 95, 96, 97, 46, 98, 99, 100, 101, 47, 54, 102, 103, 49, 104, 105, 106, 107, 50, 108, 109, 51, 110, 111, 112, 113, 52, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 53, 54, 6, 14, 11, 67, 63, 131, 57, 132, 133, 134, 135, 136, 137, 58, 138, 139, 59, 60, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 61, 62, 150, 151, 63, 7, 69, 153, 154, 155, 156, 157, 65, 33, 32, 44, 33, 0, 25, 40, 43, 66, 34, 28, 48, 169, 170, 171, 172, 173, 67, 43, 8, 30, 49, 20, 33, 4, 31, 93, 25, 5, 128, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 72, 192, 193, 73, 74, 194, 195, 196, 197, 75, 198, 199, 76, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 77, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 78, 224, 225, 226, 227, 79, 80, 228, 229, 81, 230, 231, 232, 233, 82, 234, 235, 236, 237, 238, 239, 83, 84, 240, 241, 85, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 86, 252, 253, 254, 255, 256, 257, 87, 43, 85, 3, 189, 18, 65, 24, 71, 192, 18, 1, 50, 40, 25, 20, 21, 50, 0, 25, 0, 0, ...

Run length 2 = 364. This pattern pertains to an infinite number of primes and has many defects.

s12 begins:

12, 1, 2, 1, 1, 0, 5, 2, 3, 4, 6, 7, 5, 2, 2, 0, 7, 1, 8, 10, 11, 10, 1, 1, 0, 2, 8, 2, 1, 2, 1, 1, 0, 3, 15, 21, 22, 23, 15, 1, 2, 8, 5, 19, 18, 27, 28, 29, 19, 3, 9, 30, 31, 22, 8, 6, 18, 4, 18, 0, 9, 1, 7, 32, 41, 24, 42, 43, 25, 44, 45, 46, 47, 26, 48, 49, 50, 51, 52, 53, 27, 9, 5, 29, 26, 3, 27, 3, 1, 9, 4, 9, 0, 9, 0, 0, ...

Run length 12 = 94. This pattern pertains to an infinite number of nonprimes and has many defects.

We see that there are three principal conditions of such sequences s, based upon the nature of the seed. Since s(1) = 1 for any input, the seed x = 1 begins {1, 1, 0, …}, the 0 arising from two adjacent nonprimes. Given a prime seed x = P, we have {P, 1, 1, …}, and a nonprime seed x = N, we have {N, 1, 2, …}.

Defects arise in the latter two P and N trajectories when x conflicts with the same x that arises later in the trajectory. The conflict involves converting a novel to an extant progenitor s(n), normally resulting in a vastly different report at s(n+1). A key consideration is that the novelty test when positive requires reporting the number c or (nc), with c incrementing upon the occasion of both novel and extant primes, granting opportunities for gaps in the reporting of the counting functions c or (nc) through which certain seeds x pass, so as not to disturb the canonical sequence.

Canonical Trajectories.

There are 3 “canonical trajectories” that derive from the 4 possible conditional states that govern the sequence s. These include the novel nonprime (NN) and the novel prime (NP) canonical trajectories pertaining to conditions 0 and 1, respectively. There is also an “extant” trajectory (X) that is determined by s1(1) = 1. Of course, the trajectory of x = 1 is not truly an extant one, since by definition the seed is introduced and thus novel. However, the extant condition comes into play at s1(2) = 0. We might also see x = 1 simply as a novel nonprime variant that departs at n = 2.

For all x, we have s(1) = 1, since s(0) = x is novel. Regardless of primality, for n = 1, there is 1 instance of the appropriate species (nonprime or prime) in s. If x is prime, then s(2) = 1 else s(2) = 2 except in the case of x = 1.

The Canonical Extant Trajectory.

We have already shown that, for x = 1, s1(2) = 0, since 1 has already appeared at s1(0). Therefore we report the number of primes between s0 and s1, which of course is 0.

Let’s use a sequence condition diagram that colors the term according to the conditional state imparted by s(n−1). Red indicates a novel prime progenitor, yellow a novel nonprime. Blue indicates an extant prime progenitor and green an extant nonprime. Further, we note the index n above s(n). We ignore the trivial infinite coda of zeros that follow the last nonzero term.

Figure S1:

Therefore, we see that we never have a “blue” or extant prime arise in the trajectory, and we mark the departure of the novel trajectories from this canonical extant trajectory at n = 2 with a black circle and a red dot under it.

Note there are 3 possible values for s(2); for x = 1, s1(2) = 0, for x prime we have sP(2) = 1, and for x ≠ 1 and nonprime, we have sN(2) = 2.

The Canonical Nonprime Trajectory.

Let us consider a seed x ≠ 1 and suppose it is a nonprime N that does not interfere with any element in the trajectory. Therefore, we derive a pattern sN as follows:

Figure S12:

This trajectory has length N = 94 and first arises for N = 12. We find that if ever N does appear in sN , it induces a departure from this canonical nonprime trajectory. This is because, for x = N, N already appeared at k = 0, therefore its appearance at n is its second appearance, meaning it is now an extant nonprime and triggering Condition 2 instead of Condition 0. It could be possible to end up with the canonical sequence anyway. For that to happen, Condition 2 would yield the same s(n) as Condition 0. There are only 26 conflicting nonprime seeds and all have been observed to deviate from the canonical nonprime trajectory.

Figure P12 is an annotated scatterplot of sN = s12 using the same color function:

It is interesting to note the airborne yellow path related with the reporting of the number (nc) of nonprimes in s, and the similar sparser number c of primes in s in red. Again, these counting functions escalate even though they are not reported in the extant Conditions 2 and 3. We also see generally elevated numbers of nonprimes between the last 2 instances of primes in blue, as compared to the denser and smaller numbers of primes between the last 2 instances of nonprimes in green. The plot shows the first 2 trivial zeros.

The death knell appears to be the instance of two adjacent extant numbers of the same primality status, followed by 0, then a third term of same primality status.

The Canonical Prime Trajectory.

Let us consider a prime seed x, supposing it is a prime P that does not interfere with any element in the trajectory. We produce a pattern sP as follows:

Figure S2:

This trajectory has length P = 364 and first arises for P = 2 (since it is the least prime). We find that if ever P does appear in sN , it induces a departure from this canonical prime trajectory. This is because, for x = P, P already appeared at k = 0, therefore its appearance at n is its second appearance, meaning it is now an extant prime and triggering Condition 3 instead of Condition 1. It could be possible to end up with the canonical sequence anyway. For that to happen, Condition 3 would yield the same s(n) as Condition 1. There are only 49 conflicting prime seeds and all have been observed to deviate from the canonical prime trajectory.

Figure P2 is a scatterplot of s2:

Transmissivity of the Canonical Trajectories.

Let us examine the canonical trajectories to determine the gaps in coverage that serve as “holes” in the multiset through which seeds x may pass without disturbing any element in the trajectory.

The canonical extant trajectory pertains precisely to x = 1 since s(1) = 1 for all x. There are no defects from this trajectory. We may consider s2 to be a defect from the canonical novel trajectories s2 and s12.

For the canonical prime trajectory s2, we have 2 = 364 with the maximum s2(343) = 257 and last term 25. Taking the complement of (1…257) and s2, the following numbers are not in s2:

15, 17, 42, 56, 68, 70, 129, 130, 152, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 174, 175, 176, 177, 178, 179, 180, 181.

The only primes that pass through s2 are {17, 163, 167, 179, 181}: these and all primes p > s2(343) share the trajectory s2. All the primes that interfere with the trajectory s2 present their own distinct trajectory that departs from that of s2. These 49 defects are listed below:

3, 5, 7, 11, 13, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 173, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257.

These primes p appear in the following order in s2:

(2), 3, 7, 13, 19, 11, 5, 23, 29, 31, 37, 41, 47, 67, 71, 89, 97, 101, 103, 107, 109, 113, 127, 53, 131, 137, 139, 59, 149, 61, 151, 157, 43, 173, 191, 193, 73, 197, 199, 211, 223, 227, 79, 229, 233, 239, 83, 241, 251, 257.

We see that the departure of sp from s2 occurs progressively later as to the above ordering. The concordance of sp and s2 has length k + 1, where s2(k) = p is the first appearance of p in s2. There are no departures from any sp, hence the departures on account of prime seed p occur if p appears in s2 and the conflict occurs at the first appearance s2(k) = p.

The canonical nonprime trajectory s12, we have 12 = 93 with the maximum s2(79) = 53 and last term 9. Taking the complement of (1…53) and s12, the following numbers are not in s12:

12, 13, 14, 16, 17, 20, 33, 34, 35, 36, 37, 38, 39, 40

Of these, {12, 14, 16, 20, 33, 34, 35, 36, 38, 39, 40, 54} are not in s12. These and all nonprimes m > s12(79) share the trajectory s12. Therefore, we have the following 26 conflicting nonprime seeds:

0, 4, 6, 8, 9, 10, 15, 18, 21, 22, 24, 25, 26, 27, 28, 30, 32, 42, 44, 45, 46, 48, 49, 50, 51, 52

These nonprimes m appear in the order in s12 presented below:

0, 4, 6, 8, 10, 15, 21, 22, 18, 27, 28, 9, 30, 32, 24, 42, 25, 44, 45, 46, 26, 48, 49, 50, 51, 52

We see that the departure of sm from s12 occurs progressively later as to the above ordering. The concordance of sm and s12 has length k + 1, where s12(k) = m is the first appearance of m in s12. There are no departures from any sm, hence the departures on account of nonprime seed m occur if m appears in s12 and the conflict occurs at the first appearance s12(k) = m.

It is clear that all seeds x > s2(343) = 257 do not conflict with any canonical term m, hence nonprimes share trajectory s12 and primes share trajectory s2. We see that 49 prime defects + 26 nonprime defects = 75, and we add the 3 canonical trajectories to arrive at the 78 possible trajectories of Icarus’ ever-fateful flight.

Icarus’ lamest flight starts with seed x = 0:

Figure S0:

In Figure S0 we ghosted out the terms that also appear in sN, with the collision at n = 5 in red figures. The first term that differs from sN is s0(6) = 1. This proves to be a faster fateful error! The flight has length 0 = 7.

Icarus’ most glorious and longest-lasting flight starts with the prime seed x = 43:

Figure S43 ignores the terms that agree with sP for brevity:

Figure S43 describes a sustained flight that lasts nearly 3 times as long at 43 = 902 as P = 364.

Figure P43 is a scatterplot of s43:

The longest nonprime flight pertains to x = 21 with 21 = 505.

Figure 2 is an animation of scatterplots of all 78 trajectories.

The Effect of Defection from Canon.

The canonical trajectories are those that allow the sequence sP or sN to progress unimpeded by collision with a prime seed x = p or a nonprime seed x = N. The collisions affect the first appearance of x in the canonical trajectory s, transmuting its conditional mode from a novel to an extant prime or nonprime.

The transmutation of a novel nonprime to an extant nonprime necessitates the application of Condition 2 (green) in place of Condition 0 (yellow). Therefore, instead of reporting the number (nc) of nonprimes in s, we report the number qp of primes between s(k) and s(n). The number (nc) increases quite rapidly and more often, whereas qp tends to be a “random” yet relatively small number. The later the interaction of seed x with its appearance in the canonical nonprime trajectory, the greater the tendency to “kill” the flight of Icarus.

The transmutation of a novel prime to an extant prime necessitates the application of Condition 3 (blue) in place of Condition 1 (red). Therefore, instead of reporting the number c of primes in s, we report the number qn of nonprimes between s(k) and s(n). The number c increases mildly, whereas qn tends to be a “random” and widely scattered number.

As regards the nonprime collisions, 13 result in a shortened run length and 12 prolonged, with 1 (that of x = 15) the same length 12 = 93. The mean reduction is −31.15 terms, while the mean lengthening is +79 1/3 terms. Collisions that occur near the middle of the canonical run length 12 are more likely to outlast 12. Those that happen after 72 iterations tend to reduce run length.

Regarding the prime collisions, 31 are reduced and 18 are lengthened from 2 = 364 terms. The mean reduction is −155.097 terms, while the mean lengthening is +93.44 terms. The collisions that transpire later in the canonical run length 2 tend to outlast 2. The seeds x that have a concordance with canon less than 160 terms all suffer shortened lives.

There doesn’t appear to be a pattern among the defective seeds that would either predictably prolong or reduce the flight of Icarus.

The Tree of Icarus’ Trajectories.

We can plot a tree of all the possible trajectories s by bringing together the sequence condition diagrams for all 78 distinct seeds x, rendered in a linear fashion. For the canonical trajectories, we show all terms. For the seeds x that depart from these, we need only show the terms that depart from these canonical trajectories.

Figure 1 is a tree proceeding from left to right that shows the canonical tranjectories in the middle, with nonprimes on top, 1 in the middle, and primes on the bottom, arranged in order of the appearance of defective x in canonical trajectory so as to avoid crossing leaderlines to the term of departure s(k+1). (View an enlarged abbreviated table showing conditional states and trajectory identities and lengths in italic after the nontrivial chain. View a fully annotated chart showing all 78 sequences.)

As captive of King Minos, Daedalus perhaps hadn’t considered that Icarus can’t possibly win regardless of the seed he used. Maybe he gamed it out there in the lofty cool of his cell, only after the boy took flight—all the possible trajectories Icarus could take, only to break down knowing escape wouldn’t prove possible. The question remains, could we find a seed that would allow the boy to fly away as planned? If we apply negative x, since no negative m appear in s, we would see no conflict and get the canonical nonprime trajectory (unless one construes a negative prime as a prime, as some CAS packages do). We might apply a series of initial terms, perhaps, and find an infinite and nontrivial sequence. In any case, we are fighting the propensity of the extant conditions to pull Icarus down from the novel flight path and into the sea.

Appendix:

Table A: Aggregate data for each trajectory.

Column “x” pertains to seed x; “PM” to the primality of x: x denotes the empty product, p denotes prime, n nonprime.
Column “” is the nontrivial run length of sx, while D is the index of departure from the primality-canon.
The “Modes” section counts the conditions that appear in sx. c0 pertains to novel nonprimes, c1 to novel primes, c2 to extant nonprimes, and c3 to extant primes.
The “Maximum” section pertains to the largest term in sx, listing the maximum, its index, and the instigating condition.
The “Last” section regards the last nontrivial term in sx, listing the term and the instigating condition.

                     |        Modes        |       Maximum       |   Last
                     | NN   NP    XN    XP |                     |
  x  PM     ℓ     D    c0   c1    c2    c3   max     position   c last   c
--------------------------------------------------------------------------
  1   x     7   [X]     2    1     4     0     3            3   0    1   2
--------------------------------------------------------------------------
  2   p   363   (P)   180   50    93    40   257          343   0   25   2
  3   p   153     4    55   23    50    25    97          144   0   14   2
  5   p   126    32    35   16    51    24    59           89   0    4   2
  7   p    98    12    39   17    26    16    61           93   0    9   2
 11   p    34    30     7    6    14     7    19     {29, 31}   3    4   2
 13   p    45    20    12    8    17     8    23           38   0    1   2
 19   p   207    29    78   28    71    30   127          179   0   12   2
 23   p    97    40    27   14    35    21    47           73   0    1   2
 29   p    58    47    14    9    23    12    29     {47, 48}   3    1   2
 31   p   114    51    36   15    40    23    71          107   0    8   2
 37   p    84    58    25   13    29    17    47           76   0    4   2
 41   p    95    63    30   13    34    18    47           71   0    4   2
 43   p   901   230   307   83   369   142   647          867   0    4   2
 47   p   295    71   123   40    91    41   197          275   0    1   2
 53   p   406   180   202   54   106    44   293          388   0   33   2
 59   p   202   198    82   28    59    33   139   {197, 199}   3   21   2
 61   p   462   210   184   56   152    70   317          439   0   35   2
 67   p   127    99    32   16    54    25    71          107   0    1   2
 71   p   298   107   114   38   103    43   211          291   0   15   2
 73   p   347   266   161   47    94    45   251          337   0   16   2
 79   p   403   306   173   48   121    61   257          347   0   40   2
 83   p   329   322   162   47    82    38   239   {321, 323}   3   20   2
 89   p   137   133    35   16    56    30    89   {133, 134}   3    6   2
 97   p   271   142   112   34    87    38   193          263   0    8   2
101   p   153   147    47   18    58    30   101   {147, 148}   3    8   2
103   p   324   151   149   43    87    45   223          308   0   35   2
107   p   351   156   172   49    88    42   251          341   0   38   2
109   p   166   159    55   21    59    31   109   {159, 160}   3    9   2
113   p   672   164   270   77   240    85   487          646   0    8   2
127   p   497   179   204   56   163    74   349          473   0    4   2
131   p   422   187   188   49   130    55   307          409   0    9   2
137   p   398   194   153   47   139    59   277          379   0    1   2
139   p   392   197   164   53   123    52   281          385   0   32   2
149   p   373   209   153   45   116    59   263          365   0   34   2
151   p   231   213    95   32    71    33   157          221   0    1   2
157   p   257   221   103   33    84    37   163          229   0   30   2
173   p   284   239   104   34   100    46   173   {239, 240}   3    6   2
191   p   267   262   114   35    80    38   191   {262, 263}   3    4   2
193   p   270   265   116   36    80    38   193   {265, 266}   3    9   2
197   p   461   271   194   56   149    62   337          454   0    1   2
199   p   347   274   161   48    94    44   251          337   0   14   2
211   p   394   287   176   52   108    58   269          361   0   18   2
223   p   432   300   195   52   133    52   313          414   0   25   2
227   p   374   305   180   50   103    41   277          367   0    1   2
229   p   400   309   178   52   118    52   271          365   0    8   2
233   p   347   314   156   47   101    43   233   {314, 315}   3    4   2
239   p   378   321   175   48   105    50   269          361   0    1   2
241   p   331   325   164   48    81    38   241   {325, 326}   3   21   2
251   p   484   336   228   58   142    56   353          462   0    9   2
257   p   367   343   180   50    96    41   257   {343, 344}   3    1   2
--------------------------------------------------------------------------
 12   n    93   (N)    28   13    34    18    53           79   0    9   2
  0   n     6     5     2    1     3     0     2            2   0    1   2
  4   n   180     9    63   26    60    31   109          158   0   10   2
  6   n    18    10     4    3     9     2     6           10   0    1   2
  8   n    57    18    18    9    17    13    29           47   0    9   2
  9   n   176    50    61   24    61    30   107          157   0    4   2
 10   n    32    19     8    5    13     6    13           22   0    1   2
 15   n    93    34    27   13    35    18    53           79   0    9   2
 18   n   146    44    54   20    46    26    89          133   0   28   2
 21   n   505    35   178   51   183    93   353          495   0   18   2
 22   n   137    36    53   20    44    20    89          128   0   10   2
 24   n    82    65    18   11    36    17    47           74   0    6   2
 25   n   117    68    35   16    45    21    73          108   0    9   2
 26   n    77    73    22   12    29    14    47           72   0    4   2
 27   n    54    45    11    7    24    12    27           45   0    4   2
 28   n   110    46    44   17    30    19    71          103   0    8   2
 30   n   135    51    45   19    45    26    79          121   0   12   2
 32   n   132    63    50   23    38    21    83          125   0   22   2
 42   n    99    66    25   12    42    20    53           79   0    1   2
 44   n    78    69    19   11    33    15    44           69   0    4   2
 45   n   167    70    65   24    52    26   109          157   0   28   2
 46   n   164    71    65   23    53    23   101          141   0    4   2
 48   n    78    74    23   12    29    14    48           74   0    4   2
 49   n    79    75    24   12    29    14    49           75   0    4   2
 50   n    80    76    25   12    29    14    50           76   0    4   2
 51   n    81    77    26   12    29    14    51           77   0    4   2
 52   n    82    78    27   12    29    14    52           78   0    4   2

Figure A2: Annotated scatterplot of s2, the canonical prime trajectory, showing the nontrivial terms. The color function addresses the condition instigating the term. Gold indicates a preceding novel nonprime, red a preceding novel prime. Green indicates a preceding extant nonprime, and blue indicates a preceding extant prime. The annotation shows the term m.

Figure A12: Annotated scatterplot of s12, the canonical nonprime trajectory, showing the nontrivial terms. See A2 for color function description.

Figure A37: Annotated scatterplot of s37, a distinct trajectory that defects from the canonical prime trajectory s2 at n = 59, by influence of 37 being present in the trajectory s2. The initial instance of x = 37 transmutes s(58) to an extant prime rather than novel. See A2 for color function description.

Figure A24: Annotated scatterplot of s24, a distinct trajectory that defects from the canonical nonprime trajectory s12 at n = 66, by influence of 24 being present in the trajectory s12. The initial instance of x = 24 transmutes s(65) to an extant nonprime rather than novel. See A2 for color function description.

Code 1: Generate s2:

Block[{a = {2}, c = 0},
  Do[If[And[i > 2, a[[-2 ;; -1]] == {0, 0}], Break[],
    If[FreeQ[Most@ a, #],
      If[PrimeQ[#],
        c++; AppendTo[a, c],
        AppendTo[a, i - c]],
      If[PrimeQ[#],
        c++; AppendTo[a,
          Count[a[[-FirstPosition[Reverse@ Most@ a, #][[1]] ;; -2]], _?(! PrimeQ[#] &)] ],
        AppendTo[a,
          Count[a[[-FirstPosition[Reverse@ Most@ a, #][[1]] ;; -2]], _?PrimeQ] ]]
    ] &@ a[[-1]] ], {i, Infinity}];
  a[[1 ;; -3]]]

Disclosure: throughout my 20s I used the name Icarus > Flemish “de Vlieger” = son of the flyer. This article is not about personal demise! ; )

Document Revision Record.

2021 0311 2200 Draft.