OFFSET
0,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..214
FORMULA
a(n) ~ 2 * n^(2*n) * (1 + 2/n^2 + 4/n^4 + 8/n^6 + 14/n^8 + 24/n^10), for coefficients see A015128.
MATHEMATICA
nmax = 20; Table[SeriesCoefficient[Product[(1+n^2*x^k)/(1-n^2*x^k), {k, 1, n}], {x, 0, n}], {n, 0, nmax}]
PROG
(PARI) {a(n)= polcoef(prod(k=1, n, ((1+n^2*x^k)/(1-n^2*x^k) +x*O(x^n))), n)};
for(n=0, 20, print1(a(n), ", ")) \\ G. C. Greubel, Feb 02 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, Sep 16 2017
STATUS
approved