OFFSET
0,3
FORMULA
a(n) ~ phi^(n+1), where phi = A001622 = (1+sqrt(5))/2 is the golden ratio. - Vaclav Kotesovec, Sep 22 2019
MATHEMATICA
nmax = 40; CoefficientList[Series[Product[1/(1 - x^k/(1 - x^(2*k))), {k, 1, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Sep 22 2019 *)
PROG
(PARI) N=66; x='x+O('x^N); Vec(1/prod(k=1, N, 1-x^k/(1-x^(2*k))))
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Sep 22 2019
STATUS
approved