%I #9 Sep 07 2012 13:39:53
%S 2,7,11,13,19,23,29,41,43,67,73,79,83,101,103,107,173,191,193,197,199,
%T 227,233,251,257,263,269,277,283,317,349,353,359,367,379,383,397,409,
%U 419,431,449,461,467,479,503,509
%N 23 is a square mod p.
%C Also, only entries p=1 (mod 4) of the sequence are squares mod 23 (from the quadratic reciprocity law). - _Lekraj Beedassy_, Jul 21 2004
%H Vincenzo Librandi, <a href="/A038897/b038897.txt">Table of n, a(n) for n = 1..1000</a>
%t Select[Prime[Range[100]], JacobiSymbol[23, #] != -1 &] (* _Vincenzo Librandi_, Sep 07 2012 *)
%K nonn
%O 1,1
%A _N. J. A. Sloane_.