%I #11 Sep 08 2022 08:46:03
%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 181,191,193,197,199,211,223,227,229,233,239,241,251,257,263,269,271
%N Primes p such that x^61 = 2 has a solution mod p.
%C Complement of A059230 relative to A000040.
%C Naturally this sequence is not the same as A000040. First disagreement at index 73: a(73)=373, A000040(73)=367. [_Bruno Berselli_, Sep 20 2012]
%H Vincenzo Librandi, <a href="/A216884/b216884.txt">Table of n, a(n) for n = 1..1000</a>
%t ok[p_] := Reduce[Mod[x^61 - 2, p] == 0, x, Integers] == True; Select[Prime[Range[150]], ok]
%o (Magma) [p: p in PrimesUpTo(500) | exists(t){x: x in ResidueClassRing(p) | x^61 eq 2}];
%K nonn,easy
%O 1,1
%A _Vincenzo Librandi_, Sep 19 2012