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Primes p such that x^19 = 2 has a solution mod p.
2

%I #18 Sep 08 2022 08:44:58

%S 2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,

%T 97,101,103,107,109,113,127,131,137,139,149,151,157,163,167,173,179,

%U 181,193,197,199,211,223,227,233,239,241,251,257,263,269,271,277,281

%N Primes p such that x^19 = 2 has a solution mod p.

%C Complement of A059244 relative to A000040. - _Vincenzo Librandi_, Sep 13 2012

%H R. J. Mathar, <a href="/A049551/b049551.txt">Table of n, a(n) for n = 1..1000</a>

%H <a href="/index/Pri#smp">Index entries for related sequences</a>

%t ok[p_]:= Reduce[Mod[x^19 - 2, p] == 0, x, Integers] =!= False; Select[Prime[Range[200]], ok] (* _Vincenzo Librandi_, Sep 13 2012 *)

%o (Magma) [p: p in PrimesUpTo(300) | exists(t){x : x in ResidueClassRing(p) | x^19 eq 2}]; // _Vincenzo Librandi_, Sep 13 2012

%Y Cf. A000040, A059244.

%K nonn,easy

%O 1,1

%A _N. J. A. Sloane_