OFFSET
1,1
FORMULA
a(n) = Sum_{k=0..n} n^(n-k) * binomial(n,k) * sigma_k(n).
PROG
(PARI) a(n) = sumdiv(n, d, (d+n)^n);
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Nov 21 2023
STATUS
approved