V5116

by Michael Thomas De Vlieger, updated 19 April 2023, St. Louis, Missouri.

Name

Number of symmetric semidivisor kernels of V(n) = V6(n) = A120944(n).

Data

3, 1, 1, 0, 0, 0, 0, 17, 0, 1, 0, 0, 0, 12, 0, 0, 0, 0, 0, 1, 0, 9, 0, 6, 0, 0, 8, 0, 0, 0, 0, 0, 0, 0, 0, 7, 0, 0, 4, 0, 7, 0, 0, 0, 0, 0, 0, 4, 0, 0, 6, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 3, 6, 0, 0, 2, 0, 0, 4, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 55, 0, 0, 0, 0, 0, 0, 0, 5, 0, 3, 0, 0, 0, 3, 4, 0, 0, 0, 1, 0, 4, 0, 0, 0, 1, 0, 0, 0, 0, 5, 0, 2, 0, 1, 0, 0, 0, 0

Offset

1, 1

Comments

**

References

**

Links

**

Example

Example:
1)   6: (2,3), (3,4), (8,9);
2)  10: (4,5);
3)  14: (7,8);
4)  15: ∅
5)  21: ∅
6)  22: ∅
7)  26: ∅
8)  30: (2,3), (2,5), (3,4), (3,5), (3,8), (4,5), (4,9), (5,6), (5,8), (8,9), 
        (9,10), (15,16), (24,25), (25,27), (27,32), (80,81), (125,128);

Mathematica

v0006 = Block[{k}, k = 0;
  Reap[Monitor[Do[
    If[And[CompositeQ[n], SquareFreeQ[n]], Sow[n]; Set[k, n]
  ], {n, 2^15}], n]][[-1, -1]]];
Block[{c, d, f, K, R},
  f[n_, m_ : 0] :=
  Block[{w , lim = If[m <= 0, n, m]},
     Sort@ ToExpression@
       Function[w,
         StringJoin["Block[{n = ", ToString@ lim, "}, Flatten@ Table[",
           StringJoin@
             Riffle[Map[ToString@ #1 <> "^" <> ToString@ #2 & @@ # &,
               w], " * "], ", ", Most@ Flatten@ Map[{#, ", "} &, #], "]]"] &@
         MapIndexed[
           Function[p,
                StringJoin["{", ToString@ Last@ p, ", 0, Log[",
                 ToString@ First@ p, ", n/(",
               ToString@
                InputForm[
                 Times @@ Map[Power @@ # &, Take[w, First@ #2 - 1]]],
                 ")]}"]]@ w[[First@ #2]] &, w]]@
        Map[{#, ToExpression["p" <> ToString@ PrimePi@ #]} &, #[[All, 1]]
            ] &@ FactorInteger@ n
   ];
  Map[(c = 0;
    K = #;
    R = f[K, (K^2)/2]; d = Divisors[K];
      Map[Function[k,
      c += Count[k + d, _?(And[CoprimeQ[k, #], MemberQ[R, #]] &)]],
       Rest@ R]; c) &, v0006[[1 ;; 2^14]]]
 ] (* Michael De Vlieger, May 3 2016 *)

Crossrefs

Cf. V0111, V5110, V5111, V5115, V5119.

Keyword

nonn

Author Michael De Vlieger, March 23 2023

V-series integer sequences may or may not also appear in OEIS; these are used when either the sequence is a work in progress and has to do with constitutive matters, is still being researched, or does not merit general interest at OEIS.