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Primes p such that x^40 = 2 has no solution mod p.
2

%I #9 Sep 08 2022 08:45:02

%S 3,5,11,13,17,19,29,31,37,41,43,53,59,61,67,71,83,97,101,107,109,113,

%T 131,137,139,149,157,163,173,179,181,191,193,197,211,227,229,241,251,

%U 269,271,277,281,283,293,307,311,313,317,331,347,349,353,373,379,389

%N Primes p such that x^40 = 2 has no solution mod p.

%C Complement of A049572 relative to A000040.

%H Vincenzo Librandi, <a href="/A059352/b059352.txt">Table of n, a(n) for n = 1..1000</a>

%t ok[p_] := Reduce[Mod[x^40 - 2, p] == 0, x, Integers] == False; Select[Prime[Range[80]], ok ] (* _Vincenzo Librandi_, Sep 20 2012 *)

%o (Magma) [p: p in PrimesUpTo(400) | forall{x: x in ResidueClassRing(p) | x^40 ne 2}]; // _Vincenzo Librandi_, Sep 20 2012

%Y Cf. A000040, A049572.

%K nonn,easy

%O 1,1

%A _Klaus Brockhaus_, Jan 27 2001