%I
%S 2,5,11,13,17,23,41,61,67,71,79,89,97,101,107,127,151,163,173,179,211,
%T 229,239,241,257,263,269,293,347,349,359,379,397,431,433,443,461,491,
%U 499,509,521,547,577,593,599,601,631,659,677,683,733,739,743,761,773,797,823
%N Primes with primitive root 7.
%C All terms apart from the first are == 5, 11, 13, 15, 17, 23 (mod 28) since 7 is a quadratic residue modulo any other prime. By Artin's conjecture, this sequence contains about 37.395% of all primes, that is, about 74.79% of all primes == 5, 11, 13, 15, 17, 23 (mod 28).  _Jianing Song_, Sep 05 2018
%H Vincenzo Librandi, <a href="/A019337/b019337.txt">Table of n, a(n) for n = 1..1000</a>
%H <a href="/index/Pri#primes_root">Index entries for primes by primitive root</a>
%t pr=7; Select[Prime[Range[200]], MultiplicativeOrder[pr, # ] == #1 &]
%Y Cf. A167795.
%K nonn
%O 1,1
%A _David W. Wilson_
