A216745 - OEIS

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A216745

Primes p such that x^28 = -2 has no solution mod p.

5, 7, 13, 17, 23, 29, 31, 37, 41, 43, 47, 53, 61, 71, 79, 97, 101, 103, 109, 113, 127, 137, 149, 151, 157, 167, 173, 181, 191, 193, 197, 199, 211, 223, 229, 239, 241, 263, 269, 271, 277, 281, 293, 311, 313, 317, 337, 349, 359, 367, 373, 379, 383, 389, 397, 401, 409, 421, 431, 433

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OFFSET

1,1

COMMENTS

Complement of A051083 relative to A000040.

LINKS

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

MATHEMATICA

ok[p_]:= Reduce[Mod[x^28 + 2, p] == 0, x, Integers] == False; Select[Prime[Range[110]], ok]

PROG

(Magma) [p: p in PrimesUpTo(500) | not exists{x : x in ResidueClassRing(p) | x^28 eq -2} ]; // Vincenzo Librandi, Sep 16 2012

CROSSREFS