OFFSET
1,1
COMMENTS
That the sequence is infinite can be proved using a theorem in the reference.
This sequence contains all primes congruent to 11 or 13 modulo 24, thus is infinite according to Dirichlet's theorem on arithmetic progressions. - Jianing Song, Dec 25 2018
REFERENCES
A. K. Devaraj, "Euler's generalization of Fermat's theorem-a further generalization", in ISSN #1550-3747, Proceedings of Hawaii Intl Conference on Statistics, Mathematics & Related Fields, 2004.
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
MATHEMATICA
Select[Prime[Range[135]], !MemberQ[Table[PowerMod[3, k, # ], {k, #-1}], 2]&] (* Farideh Firoozbakht, Oct 11 2006 *)
PROG
(PARI) is(n)=if(n<4, return(n>1)); if(!isprime(n) || znorder(Mod(3, n)) == n-1, return(0)); my(m=Mod(3, n)); while(m!=1, m*=3; if(m==2, return(0))); 1 \\ Charles R Greathouse IV, Jul 07 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
A.K. Devaraj, Oct 07 2006
EXTENSIONS
More terms from Don Reble, Oct 07 2006
STATUS
approved