OFFSET
1,2
FORMULA
E.g.f.: -(1/(1-x)) * Sum_{k>0} (-1)^k * (exp(x^k) - 1)/k.
E.g.f.: (1/(1-x)) * Sum_{k>0} log(1+x^k)/k!.
PROG
(PARI) a(n) = n!*sum(k=1, n, sumdiv(k, d, (-1)^(d+1)/(d*(k/d)!)));
(PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(-sum(k=1, N, (-1)^k*(exp(x^k)-1)/k)/(1-x)))
(PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(sum(k=1, N, log(1+x^k)/k!)/(1-x)))
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Aug 05 2022
STATUS
approved