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 A040160 #20 Jul 08 2025 22:53:25 %S A040160 11,31,41,61,71,101,131,181,191,211,271,281,311,331,401,421,461,491, %T A040160 521,541,601,631,661,691,701,751,761,811,821,881,941,991,1021,1031, %U A040160 1051,1061,1091,1151,1171,1201,1231,1291,1301,1321,1361,1381,1451,1471,1481,1511,1531,1571 %N A040160 Primes p such that x^5 = 2 has no solution mod p. %C A040160 Complement of A040159 relative to A000040. - _Vincenzo Librandi_, Sep 18 2012 %H A040160 Vincenzo Librandi, <a href="/A040160/b040160.txt">Table of n, a(n) for n = 1..1000</a> %t A040160 ok[p_]:= Reduce[Mod[x^5 - 2, p] == 0, x, Integers] == False; Select[Prime[Range[300]], ok] (* _Vincenzo Librandi_, Sep 18 2012 *) %o A040160 (Magma) [p: p in PrimesUpTo(1300) | forall{x: x in ResidueClassRing(p) | x^5 ne 2}]; // _Bruno Berselli_, Sep 12 2012 %o A040160 (Magma) [p: p in PrimesUpTo(1500) | not exists{x : x in ResidueClassRing(p) | x^5 eq 2} ]; // _Vincenzo Librandi_, Sep 18 2012 %o A040160 (PARI) forprime(p=2,10^3,if(#polrootsmod(x^5-2,p)==0,print1(p,", "))) \\ _Joerg Arndt_, Jul 16 2015 %K A040160 nonn,easy %O A040160 1,1 %A A040160 _N. J. A. Sloane_