OFFSET
1,2
LINKS
Seiichi Manyama, Table of n, a(n) for n = 1..464
FORMULA
E.g.f.: (1/(1-x)) * Sum_{k>0} (1 - x^k) * (exp(x^k) - 1)/k!.
MATHEMATICA
a[n_] := n! * Sum[1/(k! * Floor[n/k]!), {k, 1, n}]; Array[a, 23] (* Amiram Eldar, Jul 22 2022 *)
PROG
(PARI) a(n) = n!*sum(k=1, n, 1/(k!*(n\k)!));
(PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(sum(k=1, N, (1-x^k)*(exp(x^k)-1)/k!)/(1-x)))
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Jul 22 2022
STATUS
approved