

A010462


Squares mod 30.


7



0, 1, 4, 6, 9, 10, 15, 16, 19, 21, 24, 25
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OFFSET

1,3


COMMENTS

Range of A070452; a(k) + a(13k) = 25, 1 <= k <= 12.  Reinhard Zumkeller, Apr 24 2009


LINKS

Table of n, a(n) for n=1..12.


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

Cf. A010378, A010382, A010421.  Reinhard Zumkeller, Apr 24 2009
Row 30 of A096008.
Cf. A028743.
Sequence in context: A243485 A310665 A005659 * A028957 A242664 A084662
Adjacent sequences: A010459 A010460 A010461 * A010463 A010464 A010465


KEYWORD

nonn,fini,full


AUTHOR

N. J. A. Sloane


STATUS

approved



