A028730 Nonsquares mod 17.

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

Offset

1,1

Comments

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

Links

Table of n, a(n) for n=1..8.

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 *)

Prog

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

Crossrefs

Cf. A010379, A136806.

Sequence in context: A335657 A038550 A204232 * A028747 A136806 A253550

Adjacent sequences: A028727 A028728 A028729 * A028731 A028732 A028733

Keyword

nonn,fini,full

Author

N. J. A. Sloane

Status

approved