OFFSET
1,1
COMMENTS
Primes p such that 2 is a primitive root modulo p (i.e., p is in A001122) and that p == 1 (mod 3).
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
Eric Weisstein's World of Mathematics, Artin's constant
Wikipedia, Artin's conjecture on primitive roots
EXAMPLE
For p = 67, the multiplicative order of 2 modulo 67 is 66, while 8^22 == 2^(3*22) == 1 (mod 67), so 67 is a term.
MAPLE
select(p -> isprime(p) and numtheory:-order(2, p) = p-1,
[seq(i, i=1..10000, 6)]); # Robert Israel, Apr 23 2019
MATHEMATICA
Select[Prime@ Range[5, 310], And[FreeQ[#, 8], ! FreeQ[#, 2]] &@ PrimitiveRootList@ # &] (* Michael De Vlieger, Apr 23 2019 *)
PROG
(PARI) forprime(p=3, 2000, if(znorder(Mod(2, p))==(p-1) && p%3==1, print1(p, ", ")))
CROSSREFS
KEYWORD
nonn,changed
AUTHOR
Jianing Song, Apr 19 2019
STATUS
approved