A216690 - OEIS

%I #16 Sep 15 2012 03:18:31

%S 5,7,13,17,23,29,31,37,41,47,53,61,71,79,97,101,103,109,127,137,149,

%T 151,157,167,173,181,191,193,197,199,223,229,239,241,263,269,271,277,

%U 293,311,313,317,349,359,367,373,383,389,397

%N Primes p such that x^4 = -2 has no solution mod p.

%C Complement of A051071 relative to A000040.

%H Vincenzo Librandi, <a href="/A216690/b216690.txt">Table of n, a(n) for n = 1..1000</a>

%t ok[p_]:= Reduce[Mod[x^4 + 2, p] == 0, x, Integers] == False; Select[Prime[Range[100]], ok]

%Y Cf. A000040, A051071.

%K nonn,easy

%O 1,1

%A _Vincenzo Librandi_, Sep 15 2012