%I
%S 2,3,5,7,13,17,19,23,29,31,37,43,47,53,59,67,73,79,83,89,97,103,107,
%T 109,113,127,137,139,149,157,163,167,173,179,191,193,197,199,223,227,
%U 229,233,239,251,257,263,269,271
%N Primes p such that x^5 = 5 has a solution mod p.
%H Vincenzo Librandi, <a href="/A040165/b040165.txt">Table of n, a(n) for n = 1..1000</a>
%t ok [p_]:=Reduce[Mod[x^5 - 5, p]== 0, x, Integers]=!= False; Select[Prime[Range[150]], ok] (* _Vincenzo Librandi_, Sep 12 2012 *)
%o (Magma) [p: p in PrimesUpTo(400) | exists(t){x : x in ResidueClassRing(p) | x^5 eq 5}]; // _Vincenzo Librandi_, Sep 12 2012
%K nonn,easy
%O 1,1
%A _N. J. A. Sloane_.
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