A040087 Primes p such that x^3 = 21 has a solution mod p.

2, 3, 5, 7, 11, 13, 17, 23, 29, 41, 43, 47, 53, 59, 71, 73, 79, 83, 89, 101, 107, 113, 131, 137, 149, 163, 167, 173, 179, 191, 197, 227, 229, 233, 239, 241, 251, 257, 263, 269, 277, 281, 283, 293, 311, 317, 347, 349

Offset

1,1

Comments

Complement of A040088 relative to A000040. - Vincenzo Librandi, Sep 13 2012

Links

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

Mathematica

ok[p_]:=Reduce[Mod[x^3 - 21, p] == 0, x, Integers] =!= False;  Select[Prime[Range[180]], ok] (* Vincenzo Librandi, Sep 11 2012 *)

Prog

(Magma) [p: p in PrimesUpTo(450) | exists(t){x : x in ResidueClassRing(p) | x^3 eq 21}]; // Vincenzo Librandi, Sep 11 2012

Crossrefs

Cf. A000040, A040088.

Sequence in context: A192503 A040067 A181659 * A040065 A051647 A042986

Adjacent sequences: A040084 A040085 A040086 * A040088 A040089 A040090

Keyword

nonn,easy

Author

N. J. A. Sloane.

Status

approved