OFFSET
1,4
FORMULA
a(n) = Sum_{p|n prime} p^(n - p).
If p is prime, a(p) = 1.
PROG
(PARI) a(n) = sumdiv(n, d, isprime(d)*d^(n-d));
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Seiichi Manyama, Jun 06 2024
STATUS
approved