%I #7 Sep 08 2012 05:16:20
%S 2,3,7,11,13,23,29,31,37,41,43,53,59,83,89,101,109,137,139,151,173,
%T 191,211,223,227,229,263,269,271,281,283,311,313,337,349,353,389,397,
%U 401,421,433,449,463,487,503,523
%N Primes p such that 78 is a square mod p.
%H Vincenzo Librandi, <a href="/A038963/b038963.txt">Table of n, a(n) for n = 1..1000</a>
%t Select[Prime[Range[110]], ! JacobiSymbol[78, #] == -1 &] (* _Vincenzo Librandi_, Sep 08 2012 *)
%K nonn
%O 1,1
%A _N. J. A. Sloane_.