A028730 Nonsquares mod 17.

3, 5, 6, 7, 10, 11, 12, 14

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn
• fini
• full

Comments

Numbers n such that x^2 == n mod 17 has no solution.

Crossrefs

Cf. A010379, A136806.

Programs

Mathematica

p = 17; Complement[Range[p - 1], Union[Mod[Range[(p - 1)/2]^2, p]]]  (* Harvey P. Dale, Apr 26 2011 *)
Select[Range[0, 16], JacobiSymbol[#, 17] == -1 &] (* Alonso del Arte, Dec 17 2019 *)

Scala

(0 to 16).diff((1 to 17).map(n => (n * n) % 17)) // Alonso del Arte, Dec 17 2019