OFFSET
1,3
FORMULA
Product_{n>=1} (1 + x^n)^(a(n)/n!) = 1 - Sum_{n>=1} (-x)^n/n.
MATHEMATICA
b[n_, i_] := b[n, i] = If[n == 0, 1, If[i < 1, 0, Sum[Binomial[c[i], j] b[n - i j, i - 1], {j, 0, n/i}]]]; c[n_] := c[n] = (-1)^(n + 1)/n - b[n, n - 1]; a[n_] := n! c[n]; Table[a[n], {n, 1, 21}]
CROSSREFS
KEYWORD
sign
AUTHOR
Ilya Gutkovskiy, May 15 2022
STATUS
approved