OFFSET
0,2
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..1000
FORMULA
a(n) ~ 2^(2*n - 5/2) * exp(sqrt(n)*Pi/2) / n^(13/16). - Vaclav Kotesovec, Apr 23 2018
MAPLE
seq(coeff(series(mul(((1+(4*x)^k)/(1-(4*x)^k))^(1/4), k = 1..n), x, n+1), x, n), n = 0..35); # Muniru A Asiru, Apr 22 2018
MATHEMATICA
nmax = 30; CoefficientList[Series[Product[((1 + x^k)/(1 - x^k))^(1/4), {k, 1, nmax}], {x, 0, nmax}], x] * 4^Range[0, nmax] (* Vaclav Kotesovec, Apr 23 2018 *)
PROG
(PARI) N=66; x='x+O('x^N); Vec(prod(k=1, N, ((1+(4*x)^k)/(1-(4*x)^k))^(1/4)))
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Apr 22 2018
STATUS
approved