OFFSET
0,3
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 0..10000
FORMULA
a(n) ~ (1 + sqrt(2)) * exp(Pi*sqrt(n)) / (2^(9/2) * n).
MATHEMATICA
nmax = 60; CoefficientList[Series[Sum[x^(k^2) * Product[(1+x^j)/(1-x^j), {j, 1, k}]^2, {k, 0, Sqrt[nmax]}], {x, 0, nmax}], x]
CROSSREFS
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, Oct 06 2024
STATUS
approved