OFFSET
1,2
LINKS
MATHEMATICA
s[n_] := Module[{k = n, m = 1, p = 2}, While[k > 0, m *= (p^Min[Mod[k, p], IntegerExponent[n, p]]); k = Quotient[k, p]; p = NextPrime[p]]; m]; a[n_] := DivisorSum[n, s[#] * EulerPhi[n/#] &]; Array[a, 100] (* Amiram Eldar, Nov 27 2021 *)
PROG
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Antti Karttunen, Sep 25 2021
STATUS
approved