login
A040087
Primes p such that x^3 = 21 has a solution mod p.
2
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
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
Sequence in context: A192503 A040067 A181659 * A040065 A051647 A042986
KEYWORD
nonn,easy
AUTHOR
STATUS
approved