%I #12 Sep 08 2022 08:44:53

%S 7,19,31,37,43,61,73,79,97,103,109,139,151,157,193,223,229,271,277,

%T 283,307,331,349,373,397,421,433,439,463,499,523,541,547,571,577,601,

%U 607,613,619,661,673,709,727,751

%N Primes p such that x^3 = 5 has no solution mod p.

%C Complement of A040044 relative to A000040. - _Vincenzo Librandi_, Sep 17 2012

%H Vincenzo Librandi, <a href="/A040045/b040045.txt">Table of n, a(n) for n = 1..1000</a>

%t ok[p_]:= Reduce[Mod[x^3 - 5, p] == 0, x, Integers] == False;Select[Prime[Range[200]], ok] (* _Vincenzo Librandi_, Sep 17 2012 *)

%o (Magma) [p: p in PrimesUpTo(1000) | not exists{x : x in ResidueClassRing(p) | x^3 eq 5} ]; _Vincenzo Librandi_, Sep 17 2012

%K nonn,easy

%O 1,1

%A _N. J. A. Sloane_.