%I #16 Dec 27 2019 16:21:23
%S 0,1,4,7,9,10,13,16,19,22,25,27,28,31,34,36,37,40,43,46,49,52
%N Squares mod 54.
%t Union[PowerMod[Range[54], 2, 54]] (* _Alonso del Arte_, Dec 27 2019 *)
%o (Sage) [quadratic_residues(54)] # _Zerinvary Lajos_, May 24 2009
%o (Scala) (1 to 54).map(n => (n * n) % 54).toSet.toSeq.sorted // _Alonso del Arte_, Dec 27 2019
%Y Cf. A028767.
%K nonn,fini,full,easy
%O 1,3
%A _N. J. A. Sloane_
|