A216740 - OEIS

A216740

Primes p such that x^18 = -2 has no solution mod p.

5, 7, 13, 19, 23, 29, 31, 37, 47, 53, 61, 67, 71, 73, 79, 97, 101, 103, 109, 127, 139, 149, 151, 157, 163, 167, 173, 181, 191, 193, 197, 199, 211, 223, 229, 239, 241, 263, 269, 271, 277, 293, 307, 311, 313, 317, 331, 337, 349, 359, 367, 373, 379

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Complement of A051078 relative to A000040.

LINKS

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

MATHEMATICA

ok[p_]:= Reduce[Mod[x^18 + 2, p] == 0, x, Integers] == False; Select[Prime[Range[100]], ok]

CROSSREFS

Cf. A000040, A051078.

Sequence in context: A086844 A109269 A216752 * A216772 A216734 A114275

Adjacent sequences: A216737 A216738 A216739 * A216741 A216742 A216743

KEYWORD

nonn,easy

AUTHOR

Vincenzo Librandi, Sep 15 2012

STATUS

approved