A265829 Expansion of Product_{k>=1} 1/(1 - (4*k-2)*x^(4*k-2)).

1, 0, 2, 0, 4, 0, 14, 0, 28, 0, 66, 0, 168, 0, 350, 0, 760, 0, 1754, 0, 3692, 0, 7766, 0, 17076, 0, 35282, 0, 73232, 0, 156758, 0, 320768, 0, 658978, 0, 1380612, 0, 2808534, 0, 5732780, 0, 11849002, 0, 23997576, 0, 48701918, 0, 99744056, 0, 201405042

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, A265830.

Programs

Mathematica

nmax = 40; CoefficientList[Series[Product[1/(1 - (4*k-2)*x^(4*k-2)), {k, 1, nmax}], {x, 0, nmax}], x]

Formula

If n is even, then a(n) ~ c * 2^(n/2), where c = 6.8748052998532604456256851165148110527112306899116599334584... .