A038904 Primes p such that 30 is not a square mod p.

11, 23, 31, 41, 43, 47, 53, 59, 61, 67, 73, 79, 89, 97, 109, 131, 151, 163, 167, 173, 179, 181, 193, 197, 199, 229, 251, 263, 271, 281, 283, 293, 307, 313, 317, 337, 349, 383, 401, 419, 421, 433, 439, 449, 457

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn

Comments

Also primes p such that p divides 6^(p-1)/2 + 5^(p-1)/2 - Cino Hilliard, Sep 06 2004

Primes p such that p divides 7^(p-1)/2 - 1. - Cino Hilliard, Sep 06 2004

Links

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

Programs

Mathematica

Select[Prime@Range[120], JacobiSymbol[30, #] == -1 &] (* Vincenzo Librandi, Sep 09 2012 *)