OFFSET
1,4
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..16384
FORMULA
MATHEMATICA
f[p_, e_] := (p - 1)^e; s[1] = 1; s[n_] := Times @@ f @@@ FactorInteger[n]; a[n_] := DivisorSum[n, #*(n/# - s[n/#]) &]; Array[a, 100] (* Amiram Eldar, Nov 08 2021 *)
PROG
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Nov 08 2021
STATUS
approved