OFFSET
1,2
LINKS
FORMULA
MATHEMATICA
f[p_, e_] := NextPrime[p]^e; s[1] = 1; s[n_] := Times @@ f @@@ FactorInteger[n]; a[n_] := EulerPhi[DivisorSigma[1, s[n]]]; Array[a, 100] (* Amiram Eldar, May 10 2022 *)
PROG
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, May 10 2022
STATUS
approved