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A028803 Nonsquares mod 90. 1
2, 3, 5, 6, 7, 8, 11, 12, 13, 14, 15, 17, 18, 20, 21, 22, 23, 24, 26, 27, 28, 29, 30, 32, 33, 35, 37, 38, 39, 41, 42, 43, 44, 47, 48, 50, 51, 52, 53, 56, 57, 58, 59, 60, 62, 63, 65, 66, 67, 68, 69, 71, 72, 73, 74, 75, 77, 78, 80, 82, 83, 84, 86, 87, 88, 89 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..66.

MATHEMATICA

Complement[Range[0, 89], PowerMod[Range[90], 2, 90]] (* Alonso del Arte, Jan 03 2020 *)

PROG

(Scala) (0 to 89).diff((1 to 90).map(n => n * n % 90)) // Alonso del Arte, Jan 03 2020

CROSSREFS

Cf. A010451.

Sequence in context: A219255 A025501 A028758 * A050942 A096600 A122686

Adjacent sequences:  A028800 A028801 A028802 * A028804 A028805 A028806

KEYWORD

nonn,fini,full,easy

AUTHOR

N. J. A. Sloane

STATUS

approved

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Last modified July 26 01:49 EDT 2021. Contains 346294 sequences. (Running on oeis4.)