A040152 - OEIS

%I #9 Sep 08 2022 08:44:53

%S 2,3,7,11,13,59,61,67,79,89,97,109,127,137,151,163,167,173,179,239,

%T 251,257,263,271,293,331,353,359,379,401,419,431,433,439,443,467,479,

%U 499,503,521,541,587,607,613,619

%N Primes p such that x^4 = 22 has a solution mod p.

%H Vincenzo Librandi, <a href="/A040152/b040152.txt">Table of n, a(n) for n = 1..1000</a>

%t ok [p_]:=Reduce[Mod[x^4 - 22, p]== 0, x, Integers]=!= False; Select[Prime[Range[180]], ok] (* _Vincenzo Librandi_, Sep 12 2012 *)

%o (Magma) [p: p in PrimesUpTo(800) | exists(t){x : x in ResidueClassRing(p) | x^4 eq 22}]; // _Vincenzo Librandi_, Sep 12 2012

%K nonn,easy

%O 1,1

%A _N. J. A. Sloane_.