OFFSET
1,2
COMMENTS
No other terms below 10^15. - Max Alekseyev, Oct 18 2016
PROG
(PARI) isok(n) = Mod(5, n)^n == 6; \\ Michel Marcus, Oct 10 2016
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Seiichi Manyama, Oct 10 2016
STATUS
approved