OFFSET
0,2
LINKS
Robert Israel, Table of n, a(n) for n = 0..10000
FORMULA
a(n) ~ c^(1/4) * exp(2*sqrt(c*n)) / (2^(3/2) * sqrt(Pi) * n^(3/4)), where c = Pi^2/6 + log(1+sqrt(2))^2/2 + polylog(2, 3-2*sqrt(2))/2 - 2*polylog(2, sqrt(2)-1) = 1.18805291660775259061867850175092520191179528961165451864292...
MAPLE
N:= 100:
P:= mul(1+2*x^m- x^(2*m), m=1..N):
S:= series(P, x, N+1):
seq(coeff(S, x, n), n=0..N); # Robert Israel, Oct 01 2017
MATHEMATICA
nmax = 100; CoefficientList[Series[Product[1+2*x^k-x^(2*k), {k, 1, nmax}], {x, 0, nmax}], x]
CROSSREFS
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, Oct 01 2017
STATUS
approved