A040086 Primes p such that x^3 = 20 has no solution mod p.

13, 31, 37, 43, 67, 73, 79, 103, 109, 139, 157, 163, 181, 199, 211, 223, 229, 241, 271, 277, 283, 307, 313, 331, 337, 349, 367, 379, 397, 409, 421, 433, 439, 463, 487, 499, 547, 601, 607, 613, 631, 661, 673, 727

Offset

1,1

Comments

Complement of A040085 relative to A000040. - Vincenzo Librandi, Sep 17 2012

Links

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

Mathematica

ok[p_]:= Reduce[Mod[x^3 - 20, p] == 0, x, Integers] == False; Select[Prime[Range[200]], ok] (* Vincenzo Librandi, Sep 17 2012  *)

Prog

(Magma) [p: p in PrimesUpTo(1000) | not exists{x : x in ResidueClassRing(p) | x^3 eq 20} ]; // Vincenzo Librandi, Sep 17 2012

Crossrefs

Sequence in context: A038465 A103665 A040050 * A176181 A023274 A349636

Adjacent sequences: A040083 A040084 A040085 * A040087 A040088 A040089

Keyword

nonn,easy

Author

N. J. A. Sloane.

Status

approved