OFFSET
1,2
FORMULA
Product_{n>=1} 1 / (1 - x^n)^(a(n)/n!) = 1 - Sum_{n>=1} (-x)^n/n.
E.g.f.: Sum_{k>=1} mu(k) * log(1 + log(1 + x^k)) / k.
MATHEMATICA
nmax = 21; CoefficientList[Series[Sum[MoebiusMu[k] Log[1 + Log[1 + x^k]]/k, {k, 1, nmax}], {x, 0, nmax}], x] Range[0, nmax]! // Rest
CROSSREFS
KEYWORD
sign
AUTHOR
Ilya Gutkovskiy, May 15 2022
STATUS
approved