login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A283499
Expansion of exp( Sum_{n>=1} -A283498(n)/n*x^n ) in powers of x.
6
1, -1, -4, -23, -223, -2767, -42268, -759008, -15672223, -365639304, -9512549191, -273072804420, -8575012101043, -292422232720311, -10762617713743350, -425245537127322111, -17953822507629389009, -806668679245000383731
OFFSET
0,3
LINKS
FORMULA
G.f.: Product_{k>=1} (1 - x^k)^(k^k).
a(n) = -(1/n)*Sum_{k=1..n} A283498(k)*a(n-k) for n > 0.
MATHEMATICA
A[n_] := Sum[d^(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, 17}] (* Indranil Ghosh, Mar 11 2017 *)
PROG
(PARI) a(n) = if(n==0, 1, -(1/n)*sum(k=1, n, sumdiv(k, d, d^(d + 1))*a(n - k)));
for(n=0, 20, print1(a(n), ", ")) \\ Indranil Ghosh, Mar 11 2017
CROSSREFS
Sequence in context: A188404 A105747 A099692 * A305787 A295234 A306152
KEYWORD
sign
AUTHOR
Seiichi Manyama, Mar 09 2017
STATUS
approved