A265832 Expansion of Product_{k>=1} 1/(1 - (5*k-2)*x^(5*k-2)).

1, 0, 0, 3, 0, 0, 9, 0, 8, 27, 0, 24, 81, 13, 72, 243, 103, 216, 747, 309, 648, 2345, 927, 1967, 7547, 2781, 6214, 22641, 8371, 19474, 67923, 25531, 62518, 203802, 79097, 187554, 612253, 243947, 562700, 1842300, 764609, 1689142, 5546932, 2293870, 5077244

Offset: 0

Author

Vaclav Kotesovec, Dec 16 2015

Keywords

• nonn

Links

• Vaclav Kotesovec, Table of n, a(n) for n = 0..5000

Crossrefs

Cf. A067553, A265820, A265821, A265828, A265829, A265830.

Cf. A265831, A265833, A265834.

Programs

Mathematica

nmax = 40; CoefficientList[Series[Product[1/(1 - (5*k-2)*x^(5*k-2)), {k, 1, nmax}], {x, 0, nmax}], x]

Formula

a(n) ~ c * 3^(n/3), where

c = 1.171555591294550584937080627149625982761747171861533383233... if mod(n,3) = 0

c = 0.337047816440008855542662141834272219461954848118918717600... if mod(n,3) = 1

c = 0.518706292284531581251050944157928147536875425948432140453... if mod(n,3) = 2.