A327719 Expansion of Product_{k>=1} (1 + x^k/(1 + x^(2*k)/(1 + x^(3*k)/(1 + x^(4*k))))).

1, 1, 1, 1, 2, 3, 3, 3, 4, 6, 7, 9, 10, 12, 14, 16, 21, 24, 27, 32, 37, 45, 52, 59, 69, 76, 89, 103, 118, 137, 148, 173, 197, 225, 256, 280, 324, 362, 409, 462, 508, 579, 644, 720, 811, 892, 1006, 1114, 1243, 1389, 1519, 1701, 1882, 2090, 2316, 2538, 2825, 3110, 3437, 3795, 4153

Offset: 0

Author

Seiichi Manyama, Sep 23 2019

Keywords

• nonn

Links

• Seiichi Manyama, Table of n, a(n) for n = 0..1000

Crossrefs

Cf. A327716, A327717, A327718, A327720.

Programs

Mathematica

nmax = 60; CoefficientList[Series[Product[(1 + x^k + x^(2*k) + x^(3*k) + 2*x^(4*k) + x^(5*k) + x^(6*k)) / (1 + x^(2*k) + x^(3*k) + x^(4*k) + x^(6*k)), {k, 1, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Sep 23 2019 *)

PARI

N=66; x='x+O('x^N); Vec(prod(k=1, N, 1+x^k/(1+x^(2*k)/(1+x^(3*k)/(1+x^(4*k))))))