A327720 Expansion of Product_{k>=1} (1 + x^k/(1 + x^(2*k)/(1 + x^(3*k)/(1 + x^(4*k)/(1 + x^(5*k)))))).

1, 1, 1, 1, 2, 3, 3, 3, 4, 6, 7, 9, 10, 12, 14, 17, 21, 23, 26, 32, 40, 46, 51, 57, 68, 80, 91, 102, 115, 135, 156, 180, 197, 219, 250, 290, 333, 364, 403, 456, 526, 594, 648, 708, 803, 922, 1037, 1128, 1223, 1373, 1560, 1752, 1902, 2062, 2300, 2613, 2926, 3149, 3378, 3740

Offset

0,5

Comments

a(169) = -3504817 < 0.

Links

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

Mathematica

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

Prog

(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)/(1+x^(5*k)))))))

Crossrefs

Cf. A327716, A327717, A327718, A327719.

Sequence in context: A174522 A327719 A327716 * A327718 A035581 A171628

Adjacent sequences: A327717 A327718 A327719 * A327721 A327722 A327723

Keyword

sign,look

Author

Seiichi Manyama, Sep 23 2019

Status

approved