A040172 - OEIS

A040172

Primes p such that x^5 = 7 has no solution mod p.

11, 31, 41, 61, 71, 101, 131, 151, 191, 211, 241, 251, 271, 281, 331, 401, 421, 431, 461, 491, 521, 541, 571, 601, 631, 641, 691, 701, 751, 761, 821, 881, 941, 991, 1021, 1051, 1061, 1091, 1181, 1231, 1291

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OFFSET

1,1

COMMENTS

Complement of A040171 relative to A000040. - Vincenzo Librandi, Sep 18 2012

LINKS

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

MATHEMATICA

ok[p_]:= Reduce[Mod[x^5 - 7, p] == 0, x, Integers] == False; Select[Prime[Range[300]], ok] (* Vincenzo Librandi, Sep 18 2012 *)

PROG

(Magma) [p: p in PrimesUpTo(1500) | not exists{x : x in ResidueClassRing(p) | x^5 eq 7} ]; // Vincenzo Librandi, Sep 18 2012

CROSSREFS

Sequence in context: A059313 A040975 A188384 * A040160 A040981 A181603

Adjacent sequences: A040169 A040170 A040171 * A040173 A040174 A040175

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane

STATUS

approved