A010403 Squares mod 42.

0, 1, 4, 7, 9, 15, 16, 18, 21, 22, 25, 28, 30, 36, 37, 39

Offset

1,3

Links

Table of n, a(n) for n=1..16.

Mathematica

Union[PowerMod[Range[42], 2, 42]] (* Alonso del Arte, Dec 21 2019 *)

Prog

(Sage) [quadratic_residues(42)] # Zerinvary Lajos, May 24 2009
(Scala) (1 to 42).map(n => (n * n) % 42).toSet.toSeq.sorted // Alonso del Arte, Dec 21 2019

Crossrefs

Cf. A028755.

Sequence in context: A282058 A210497 A010383 * A032709 A243172 A370523

Adjacent sequences: A010400 A010401 A010402 * A010404 A010405 A010406

Keyword

nonn,fini,full,easy

Author

N. J. A. Sloane

Status

approved