OFFSET
1,2
COMMENTS
No other terms below 10^15. Some larger terms: 60092749466423900486673922957841, 401021769827858799355246286337987697472836927856337282726789534497163. - Max Alekseyev, Oct 15 2016
MATHEMATICA
Do[If[Mod[(PowerMod[5, n, n]-2), n]==0, Print[n]], {n, 1000000000}]
PROG
(PARI) is(n)=Mod(5, n)^n==2 \\ Charles R Greathouse IV, Nov 04 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
Farideh Firoozbakht, Nov 19 2006
EXTENSIONS
a(6)-a(8) from Max Alekseyev, Jul 28 2009, Jun 02 2010, Oct 15 2016
STATUS
approved