OFFSET
0,5
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 0..10000
FORMULA
a(n) ~ 5^(1/4) * exp(sqrt(5*n/2)*Pi/3) / (2^(5/4)*3*n^(3/4)). - Vaclav Kotesovec, Sep 23 2019
MATHEMATICA
nmax = 100; CoefficientList[Series[Product[1 + x^k/(1 + x^(2*k)), {k, 1, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Sep 23 2019 *)
nmax = 100; CoefficientList[Series[Product[(1 + x^k + x^(2*k)) * (1 - x^(4*k - 2)), {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))))
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Sep 23 2019
STATUS
approved