OFFSET
1,2
FORMULA
If p is prime, a(p) = p-1 + p^p = A231712(p).
MATHEMATICA
a[n_] := Sum[GCD[k, n]^k, {k, 1, n}]; Array[a, 20] (* Amiram Eldar, Mar 13 2021 *)
PROG
(PARI) a(n) = sum(k=1, n, gcd(k, n)^k);
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Mar 13 2021
STATUS
approved