OFFSET
1,2
COMMENTS
Some larger terms: 10157607413638637338691, 678641208236297002873422185407157785099272404809011007522511134591325167. - Max Alekseyev, Oct 20 2016
MATHEMATICA
Select[Range[1000000], IntegerQ[(PowerMod[5, #, # ]-3)/# ]&]
Do[If[IntegerQ[(PowerMod[5, n, n ]-3)/n], Print[n]], {n, 10^9}] (* Ryan Propper, Dec 30 2006 *)
PROG
(PARI) is(n)=Mod(5, n)^n==3 \\ Charles R Greathouse IV, Nov 04 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
Alexander Adamchuk, Nov 04 2006
EXTENSIONS
More terms from Farideh Firoozbakht, Nov 18 2006
Corrected and extended by Ryan Propper, Jan 01 2007
Entry revised by N. J. A. Sloane, Jan 24 2007
a(18) from Lars Blomberg, Dec 12 2011
a(19)-a(26) from Max Alekseyev, Oct 20 2016
STATUS
approved