OFFSET
1,2
EXAMPLE
6 is a term since iphi(6) = 2 is a divisor of 6.
MATHEMATICA
f[p_, e_] := p^(2^(-1 + Position[Reverse @ IntegerDigits[e, 2], 1])); a[1] = 1; iphi[n_] := Times @@ (Flatten@(f @@@ FactorInteger[n]) - 1); Select[Range[10^5], Divisible[#, a[#]] &]
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, Jun 01 2020
STATUS
approved