cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A300277 G.f.: 1 + Sum_{n>=1} a(n)*x^n/(1 - x^n) = Product_{n>=1} 1/(1 - n*x^n).

Original entry on oeis.org

1, 2, 5, 11, 24, 48, 96, 184, 348, 645, 1169, 2140, 3761, 6687, 11645, 20326, 34635, 59854, 100579, 171211, 285718, 479325, 791315, 1318955, 2156805, 3553589, 5783306, 9445861, 15250215, 24759156, 39713787, 63991400, 102197851, 163548416, 259744930, 413761633, 653715967
Offset: 1

Views

Author

Ilya Gutkovskiy, Mar 01 2018

Keywords

Comments

Moebius transform of A006906.

Crossrefs

Programs

  • Mathematica
    nn = 37; f[x_] := 1 + Sum[a[n] x^n/(1 - x^n), {n, 1, nn}]; sol = SolveAlways[0 == Series[f[x] - Product[1/(1 - n x^n), {n, 1, nn}], {x, 0, nn}], x]; Table[a[n], {n, 1, nn}] /. sol // Flatten
    s[n_] := SeriesCoefficient[Product[1/(1 - k x^k), {k, 1, n}], {x, 0, n}]; a[n_] := Sum[MoebiusMu[n/d] s[d], {d, Divisors[n]}]; Table[a[n], {n, 1, 37}]

Formula

a(n) = Sum_{d|n} mu(n/d)*A006906(d).