OFFSET
1,2
LINKS
Max Alekseyev, Table of n, a(n) for n = 1..649
EXAMPLE
phi(2228224)=(2*2*2*8*2*2*4)^2, so 2228224 is in the sequence.
MATHEMATICA
Do[If[Apply[Times, IntegerDigits[n]]^2==EulerPhi[n], Print[n]], {n, 1200000}]
Select[Range[94*10^5], EulerPhi[#]==(Times@@IntegerDigits[#])^2&] (* Harvey P. Dale, May 03 2020 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Farideh Firoozbakht, Jan 02 2009
EXTENSIONS
a(33)-a(649) from Max Alekseyev, Aug 18 2013, May 31 2018
STATUS
approved