This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A216741 #4 Sep 15 2012 14:12:01 %S A216741 5,7,11,13,17,23,29,31,37,41,47,53,61,71,79,97,101,103,109,127,131, %T A216741 137,149,151,157,167,173,181,191,193,197,199,211,223,229,239,241,263, %U A216741 269,271,277,281,293,311,313,317,331,349,359,367,373,383,389,397,401 %N A216741 Primes p such that x^20 = -2 has no solution mod p. %C A216741 Complement of A051079 relative to A000040. %H A216741 Vincenzo Librandi, <a href="/A216741/b216741.txt">Table of n, a(n) for n = 1..1000</a> %t A216741 ok[p_]:= Reduce[Mod[x^20 + 2, p] == 0, x, Integers] == False; Select[Prime[Range[100]], ok] %Y A216741 Cf. A000040, A051079. %K A216741 nonn,easy %O A216741 1,1 %A A216741 _Vincenzo Librandi_, Sep 15 2012