OFFSET
0,3
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 0..1000
FORMULA
a(n) ~ exp(3^(4/3) * Pi^(2/3) * Zeta(3)^(1/3) * n^(2/3) / 2^(7/3) - Pi^(4/3) * n^(1/3) / (2^(8/3) * 3^(4/3) * Zeta(3)^(1/3)) - Pi^2 / (2592 * Zeta(3))) * Zeta(3)^(1/6) / (2^(7/6) * 3^(1/3) * Pi^(1/6) * n^(2/3)).
MATHEMATICA
nmax = 40; CoefficientList[Series[Exp[Sum[-(-1)^j * Sum[DivisorSum[k, # / GCD[#, 2] &] * x^(j*k) / j, {k, 1, Floor[nmax/j] + 1}], {j, 1, nmax}]], {x, 0, nmax}], x] (* Vaclav Kotesovec, Mar 31 2018 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, Mar 26 2018
STATUS
approved