OFFSET
1,2
COMMENTS
The unitary version of A048290.
LINKS
EXAMPLE
32 is in the sequence since A177754(32) = 384 = 32 * 12 is divisible by 32.
MATHEMATICA
uphi[1] = 1; uphi[n_] := Product[{p, e} = pe; p^e-1, {pe, FactorInteger[n]}]; seq={}; s = 0; Do[s = s + uphi[n]; If[Divisible[s, n], AppendTo[seq, n]], {n, 1, 10^6}]; seq (* after Jean-François Alcover at A047994 *)
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Amiram Eldar, Mar 17 2019
STATUS
approved