OFFSET
1,1
LINKS
Donovan Johnson, Table of n, a(n) for n = 1..1000
EXAMPLE
sigma(110) + phi(110) = 256 = 4^4.
PROG
(PARI) isok(n) = ispower(sigma(n) + eulerphi(n), 4); \\ Michel Marcus, Jan 09 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
Giovanni Resta, Feb 13 2006
STATUS
approved