A010442 Squares mod 81.

0, 1, 4, 7, 9, 10, 13, 16, 19, 22, 25, 28, 31, 34, 36, 37, 40, 43, 46, 49, 52, 55, 58, 61, 63, 64, 67, 70, 73, 76, 79

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn
• fini
• full
• easy

Crossrefs

Cf. A028794, A055047.

Programs

Mathematica

Union[PowerMod[Range[81], 2, 81]] (* Alonso del Arte, Dec 27 2019 *)

Sage

[quadratic_residues(81)] # Zerinvary Lajos, May 28 2009

Scala

(1 to 81).map(n => (n * n) % 81).toSet.toSeq.sorted // Alonso del Arte, Dec 27 2019