OFFSET
1,3
FORMULA
E.g.f.: -Sum_{p prime} log(1-x^p)/p.
MATHEMATICA
a[n_] := (n-1)! * PrimeNu[n]; Array[a, 25] (* Amiram Eldar, Mar 02 2022 *)
PROG
(PARI) a(n) = (n-1)!*omega(n);
(PARI) my(N=40, x='x+O('x^N)); concat(0, Vec(serlaplace(-sum(k=1, N, isprime(k)*log(1-x^k)/k))))
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Mar 02 2022
STATUS
approved