OFFSET
1,2
LINKS
Seiichi Manyama, Table of n, a(n) for n = 1..386
FORMULA
a(n) = Sum_{k=1..n} k^n * Sum_{d|k} (1 - (1 - 1/d)^n).
MATHEMATICA
a[n_] := Sum[(k * Floor[n/k])^n, {k, 1, n}]; Array[a, 18] (* Amiram Eldar, Jul 30 2022 *)
PROG
(PARI) a(n) = sum(k=1, n, (k*(n\k))^n);
(PARI) a(n) = sum(k=1, n, k^n*sumdiv(k, d, 1-(1-1/d)^n));
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Jul 30 2022
STATUS
approved