A040112 Primes p such that x^4 = 7 has a solution mod p.

2, 3, 7, 19, 29, 31, 37, 47, 59, 83, 103, 109, 113, 131, 139, 167, 193, 199, 223, 227, 251, 271, 283, 307, 311, 367, 383, 389, 419, 439, 449, 457, 467, 479, 503, 523, 563, 587, 607, 613, 619, 643, 647, 653, 691

Offset

1,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Mathematica

ok [p_]:=Reduce[Mod[x^4- 7, p] == 0, x, Integers] =!= False;  Select[Prime[Range[200]], ok] (* Vincenzo Librandi, Sep 11 2012 *)

Prog

(Magma) [p: p in PrimesUpTo(800) | exists(t){x : x in ResidueClassRing(p) | x^4 eq 7}]; // Vincenzo Librandi, Sep 11 2012

Crossrefs

Sequence in context: A349622 A078373 A038878 * A246373 A074855 A038935

Adjacent sequences: A040109 A040110 A040111 * A040113 A040114 A040115

Keyword

nonn,easy

Author

N. J. A. Sloane.

Status

approved