%I #27 Nov 30 2019 16:45:24
%S 0,1,4,6,9,10,15,16,19,21,24,25
%N Squares mod 30.
%C Range of A070452; a(k) + a(13-k) = 25, 1 <= k <= 12. - _Reinhard Zumkeller_, Apr 24 2009
%e 3^2 = 9, so 9 is in the sequence.
%e 10^2 and 20^2 are both congruent to 10 mod 30, so 10 is in the sequence.
%e There are no solutions to x^2 = 11 mod 30, so 11 is not in the sequence.
%t Union[PowerMod[Range[30], 2, 30]] (* _Alonso del Arte_, Jan 30 2018 *)
%o (Sage) [quadratic_residues(30)] # _Zerinvary Lajos_, May 24 2009
%o (Scala) (1 to 30).map(n => n * n).map(_ % 30).toSet.toSeq.sorted // _Alonso del Arte_, Nov 30 2019
%Y Cf. A010378, A010382, A010421. - _Reinhard Zumkeller_, Apr 24 2009
%Y Row 30 of A096008.
%Y Cf. A028743.
%K nonn,fini,full
%O 1,3
%A _N. J. A. Sloane_