%I #15 Sep 08 2022 08:44:58
%S 2,7,17,23,47,73,79,89,97,103,113,127,137,167,193,199,223,233,239,241,
%T 257,263,313,337,353,359,367,383,409,431,433,439,449,457,463,479,487,
%U 503,569,577,593,599,607,617,641,647,673,719,727,743,769,809,823,839
%N Primes p such that x^50 = 2 has a solution mod p.
%C Complement of A059639 relative to A000040. - _Vincenzo Librandi_, Sep 14 2012
%H R. J. Mathar, <a href="/A049582/b049582.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^50 - 2, p] == 0, x, Integers] =!= False; Select[Prime[Range[200]], ok] (* _Vincenzo Librandi_, Sep 14 2012 *)
%o (Magma) [p: p in PrimesUpTo(900) | exists(t){x : x in ResidueClassRing(p) | x^50 eq 2}]; // _Vincenzo Librandi_, Sep 14 2012
%Y Cf. A000040, A059639.
%K nonn,easy
%O 1,1
%A _N. J. A. Sloane_
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