%I #20 Dec 20 2019 20:44:18
%S 0,1,4,5,9,16
%N Squares mod 20.
%C Range of A070442. - _Reinhard Zumkeller_, Apr 24 2009
%t Union[PowerMod[Range[20], 2, 20]] (* _Alonso del Arte_, Dec 20 2019 *)
%o (Sage) [quadratic_residues(20)] # _Zerinvary Lajos_, May 24 2009
%o (Scala) (1 to 20).map(n => (n * n) % 20).toSet.toSeq.sorted // _Alonso del Arte_, Dec 20 2019
%Y Cf. A010378, A010462, A010421. - _Reinhard Zumkeller_, Apr 24 2009
%Y Row 20 of A096008.
%Y Cf. A028733.
%K nonn,fini,full,easy
%O 1,3
%A _N. J. A. Sloane_