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%I #9 Sep 07 2012 13:47:27
%S 2,3,5,11,23,31,41,43,79,83,97,101,109,113,127,139,149,151,157,167,
%T 173,179,193,199,223,233,239,251,257,263,271,281,293,317,331,347,349,
%U 367,373,383,397,421,463,487,491
%N 31 is a square mod p.
%C Also, only entries p=1 (mod 4) of the sequence are squares mod 31 (from the quadratic reciprocity law). - _Lekraj Beedassy_, Jul 21 2004
%H Vincenzo Librandi, <a href="/A038905/b038905.txt">Table of n, a(n) for n = 1..1000</a>
%t Select[Prime[Range[100]], JacobiSymbol[31, #] != -1 &] (* _Vincenzo Librandi_, Sep 07 2012 *)
%K nonn
%O 1,1
%A _N. J. A. Sloane_.