OFFSET
1,3
COMMENTS
Möbius transform of A336853.
LINKS
FORMULA
MATHEMATICA
f[p_, e_] := NextPrime[p]^e; a[n_] := EulerPhi[Times @@ f @@@ FactorInteger[n]] - EulerPhi[n]; Array[a, 100] (* Amiram Eldar, Nov 27 2021 *)
PROG
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Aug 19 2021
STATUS
approved