A265820 Expansion of Product_{k>=1} 1/(1 - (3*k-1)*x^(3*k-1)).

1, 0, 2, 0, 4, 5, 8, 10, 24, 20, 73, 51, 146, 142, 306, 409, 731, 835, 1662, 1828, 3969, 4251, 8256, 9525, 17814, 22565, 38629, 47424, 82916, 101387, 185271, 218421, 386140, 468783, 806005, 1040428, 1696283, 2160026, 3567221, 4498026, 7683250, 9446666

Offset

0,3

Links

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

Formula

a(n) ~ c * 2^(n/2), where

c = 14.317325023208603416271945494838289608390197678435231... if n is even,

c = 13.388403642510880418401945468592189683402616378443965... if n is odd.

Mathematica

nmax = 40; CoefficientList[Series[Product[1/(1 - (3*k-1)*x^(3*k-1)), {k, 1, nmax}], {x, 0, nmax}], x]

Crossrefs

Cf. A067553, A265821.

Sequence in context: A004178 A068333 A121451 * A096984 A213723 A104601

Adjacent sequences: A265817 A265818 A265819 * A265821 A265822 A265823

Keyword

nonn

Author

Vaclav Kotesovec, Dec 15 2015

Status

approved