OFFSET
1,2
COMMENTS
No other terms below 10^15. A large term: 2455610470454186971078168169. - Max Alekseyev, Dec 19 2017
MATHEMATICA
Join[{1}, Select[Range[1, 9000], Mod[13^#, #] == 6 &]] (* G. C. Greubel, Nov 19 2017 *)
Join[{1}, Select[Range[10000000], PowerMod[13, #, #] == 6 &]] (* Robert Price, Apr 10 2020 *)
PROG
(PARI) isok(n) = Mod(13, n)^n == 6; \\ Michel Marcus, Nov 19 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Feb 19 2006
EXTENSIONS
More terms from Ryan Propper, Mar 30 2007
Term 1 is prepended and a(11)-a(15) added by Max Alekseyev, Jun 29 2011, Dec 19 2017
STATUS
approved