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A010462 Squares mod 30. 7
0, 1, 4, 6, 9, 10, 15, 16, 19, 21, 24, 25 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
COMMENTS
Range of A070452; a(k) + a(13-k) = 25, 1 <= k <= 12. - Reinhard Zumkeller, Apr 24 2009
LINKS
EXAMPLE
3^2 = 9, so 9 is in the sequence.
10^2 and 20^2 are both congruent to 10 mod 30, so 10 is in the sequence.
There are no solutions to x^2 = 11 mod 30, so 11 is not in the sequence.
MATHEMATICA
Union[PowerMod[Range[30], 2, 30]] (* Alonso del Arte, Jan 30 2018 *)
PROG
(Sage) [quadratic_residues(30)] # Zerinvary Lajos, May 24 2009
(Scala) (1 to 30).map(n => n * n).map(_ % 30).toSet.toSeq.sorted // Alonso del Arte, Nov 30 2019
CROSSREFS
Row 30 of A096008.
Cf. A028743.
Sequence in context: A243485 A310665 A005659 * A028957 A242664 A084662
KEYWORD
nonn,fini,full
AUTHOR
STATUS
approved

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Last modified February 29 09:21 EST 2024. Contains 370418 sequences. (Running on oeis4.)