%I #18 Dec 14 2019 08:15:59
%S 0,1,2,4,7,8,9,11
%N Squares mod 14.
%t Union[PowerMod[Range[14], 2, 14]] (* _Alonso del Arte_, Dec 14 2019 *)
%o (Sage) [quadratic_residues(14)] # _Zerinvary Lajos_, May 24 2009
%o (Scala) (1 to 14).map(n => (n * n) % 14).toSet.toSeq.sorted // _Alonso del Arte_, Dec 14 2019
%Y Cf. A028727.
%K nonn,fini,full
%O 1,3
%A _N. J. A. Sloane_