A040986 Primes p such that x^5 = 21 has a solution mod p.

2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 37, 43, 47, 53, 59, 61, 67, 73, 79, 83, 89, 97, 103, 107, 109, 113, 127, 137, 139, 149, 157, 163, 167, 173, 179, 193, 197, 199, 223, 227, 229, 233, 239, 257, 263, 269, 277, 283

Offset

1,1

Comments

Complement of A040987 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^5-21, p]==0, x, Integers]=!=False; Select[Prime[Range[150]], ok] (* Vincenzo Librandi, Sep 13 2012 *)

Prog

(Magma) [p: p in PrimesUpTo(400) | exists(t){x : x in ResidueClassRing(p) | x^5 eq 21}]; // Vincenzo Librandi, Sep 13 2012

Crossrefs

Cf. A000040, A040987.

Sequence in context: A077500 A036955 A040179 * A040990 A040177 A040184

Adjacent sequences: A040983 A040984 A040985 * A040987 A040988 A040989

Keyword

nonn,easy

Author

N. J. A. Sloane.

Status

approved