OFFSET
1,1
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
EXAMPLE
26 is a member of the sequence since 5^26 (mod 26) == 25.
MATHEMATICA
Select[Range@ 225, (p = PowerMod[5, #, #]) > 1 && IntegerQ@ Log[5, p] && CompositeQ[#] &] (* corrected by Amiram Eldar, Jul 24 2021 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Robert G. Wilson v, Apr 17 2007
STATUS
approved