OFFSET
1,2
EXAMPLE
p(32550001)-32550001 = 236421376 = 592240896 = 156^4.
PROG
(PARI) isok(n) = ispower(prime(n) - n, 4); \\ Michel Marcus, Jan 22 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
Giovanni Resta, Feb 13 2006
STATUS
approved