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A010442 Squares mod 81. 1
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..31.

MATHEMATICA

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

PROG

(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

CROSSREFS

Cf. A028794.

Sequence in context: A242660 A010389 A010415 * A055047 A234429 A291201

Adjacent sequences:  A010439 A010440 A010441 * A010443 A010444 A010445

KEYWORD

nonn,fini,full,easy

AUTHOR

N. J. A. Sloane

STATUS

approved

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Last modified November 28 16:34 EST 2021. Contains 349413 sequences. (Running on oeis4.)