A051084 - OEIS

%I #15 Sep 08 2022 08:44:59

%S 2,3,17,43,59,83,89,107,113,137,179,227,233,251,257,283,307,347,353,

%T 419,433,443,449,457,467,499,563,569,587,593,617,641,643,659,683,739,

%U 809,827,857,929,947,953,971,977,1019,1049,1097,1163,1187,1193,1217,1259,1283,1289,1307,1409

%N Primes p such that x^30 = -2 has a solution mod p.

%C Complement of A216746 relative to A000040. - _Vincenzo Librandi_, Sep 17 2012

%H Vincenzo Librandi, <a href="/A051084/b051084.txt">Table of n, a(n) for n = 1..1000</a>

%t ok[p_]:= Reduce[Mod[x^30 + 2, p] == 0, x, Integers] =!= False; Select[Prime[Range[500]], ok] (* _Vincenzo Librandi_, Sep 15 2012 *)

%o (PARI) /* see A051071 */

%o (Magma) [p: p in PrimesUpTo(1410) | exists(t){x : x in ResidueClassRing(p) | x^30 eq - 2}]; // _Vincenzo Librandi_, Sep 15 2012

%K nonn,easy

%O 1,1

%A _N. J. A. Sloane_

%E More terms from _Joerg Arndt_, Jul 27 2011