OFFSET
1,2
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
EXAMPLE
phi of the sequence includes 1, 128, 16384, 279936, etc..; powers arise several times; a(3) = A053576(7) = 255; in sequence rather large jumps arise when power of new numbers appear.
MATHEMATICA
k=7; Do[s=EulerPhi[n]^(1/k); If[IntegerQ[s], Print[n]], {n, 1, 1000000}]
PROG
(PARI) is(n)=ispower(eulerphi(n), 7) \\ Charles R Greathouse IV, Apr 24 2020
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Nov 27 2002
STATUS
approved