A216776 Primes p such that x^62 = -2 has no solution mod p.

5, 7, 13, 23, 29, 31, 37, 47, 53, 61, 71, 79, 101, 103, 109, 127, 149, 151, 157, 167, 173, 181, 191, 197, 199, 223, 229, 239, 263, 269, 271, 277, 293, 311, 317, 349, 359, 367, 373, 383, 389, 397, 421, 431, 439, 461, 463, 479, 487, 503, 509, 541, 557, 599

Offset: 1

Author

Vincenzo Librandi, Sep 16 2012

Keywords

• nonn
• easy

Comments

Complement of A051100 relative to A000040.

a(n) = A045355(n+1) up to n=116, and then both sequences start to differ substantially. - R. J. Mathar, Sep 19 2012

Links

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

Crossrefs

Cf. A000040, A051100.

Programs

Magma

[p: p in PrimesUpTo(700) | not exists{x : x in ResidueClassRing(p) | x^62 eq -2} ];

Mathematica

ok[p_]:=Reduce[Mod[x^62 + 2, p] == 0, x, Integers] == False;Select[Prime[Range[220]], ok]