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
Offset: 1
Links
- Vincenzo Librandi, Table of n, a(n) for n = 1..1000
Programs
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Magma
[p: p in PrimesUpTo(500) | not exists{x : x in ResidueClassRing(p) | x^28 eq -2} ]; // Vincenzo Librandi, Sep 16 2012 -
Mathematica
ok[p_]:= Reduce[Mod[x^28 + 2, p] == 0, x, Integers] == False; Select[Prime[Range[110]], ok]
Comments