OFFSET
0,2
FORMULA
From Vaclav Kotesovec, May 11 2022: (Start)
G.f.: 1/(1-x)^2 * Product_{k>=1} 1/(1-x^k)^3.
a(n) ~ exp(Pi*sqrt(2*n)) / (2^(5/2) * Pi^2 * sqrt(n)). (End)
MAPLE
a:= proc(n) option remember; `if`(n=0, 1, add(
a(n-j)*(2+3*numtheory[sigma](j)), j=1..n)/n)
end:
seq(a(n), n=0..35); # Alois P. Heinz, May 11 2022
MATHEMATICA
nmax = 35; CoefficientList[Series[1/(1 - x)^2 * Product[1/(1 - x^k)^3, {k, 1, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, May 11 2022 *)
PROG
(PARI) lista(nn) = Vec(1/(eta('x+O('x^nn))^3*(1-x)^2)); \\ Michel Marcus, May 09 2022
CROSSREFS
KEYWORD
nonn
AUTHOR
Omar E. Pol, May 08 2022
STATUS
approved