OFFSET
0,3
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..152
FORMULA
G.f.: Product_{k>=1} (1 - x^k)^(k^(3*k)).
a(n) = -(1/n)*Sum_{k=1..n} A283535(k)*a(n-k) for n > 0.
MATHEMATICA
A[n_] := Sum[d^(3*d + 1), {d, Divisors[n]}]; a[n_]:=If[n==0, 1, -(1/n)*Sum[A[k]*a[n - k], {k, n}]]; Table[a[n], {n, 0, 12}] (* Indranil Ghosh, Mar 11 2017 *)
PROG
(PARI) A(n) = sumdiv(n, d, d^(3*d + 1));
a(n) = if(n==0, 1, -(1/n)*sum(k=1, n, A(k)*a(n - k)));
for(n=0, 12, print1(a(n), ", ")) \\ Indranil Ghosh, Mar 11 2017
CROSSREFS
KEYWORD
sign
AUTHOR
Seiichi Manyama, Mar 10 2017
STATUS
approved