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.

A329276 Expansion of 1 / (1 - Sum_{k>=1} mu(2*k) * log(1 - 2 * x^k) / (2 * k)), where mu = A008683.

Original entry on oeis.org

1, 1, 2, 4, 9, 20, 45, 102, 232, 528, 1204, 2748, 6276, 14342, 32787, 74976, 171495, 392337, 897696, 2054232, 4701202, 10759689, 24627245, 56370546, 129034271, 295373313, 676158166, 1547869038, 3543458906, 8111974160, 18570800837, 42514665175, 97330789942, 222825306335
Offset: 0

Views

Author

Ilya Gutkovskiy, Nov 11 2019

Keywords

Comments

Invert transform of A000048.

Crossrefs

Programs

  • Mathematica
    nmax = 33; CoefficientList[Series[1/(1 - Sum[MoebiusMu[2 k] Log[1 - 2 x^k]/(2 k), {k, 1, nmax}]), {x, 0, nmax}], x]
    a[0] = 1; a[n_] := a[n] = Sum[(1/(2 k)) DivisorSum[k, MoebiusMu[#] 2^(k/#) &, OddQ] a[n - k], {k, 1, n}]; Table[a[n], {n, 0, 33}]

Formula

a(0) = 1; a(n) = Sum_{k=1..n} A000048(k) * a(n-k).