%I #7 May 03 2020 16:23:48
%S 2,3,5,8,12,14,18,19,20,21,22,23,26,27,30,31,32,33,34,35,39,41,45,48,
%T 50,51
%N Nonsquares mod 53.
%t Complement[Range[0, 52], PowerMod[Range[53], 2, 53]] (* _Alonso del Arte_, May 03 2020 *)
%o (Scala) (0 to 52).diff((1 to 53).map(n => n * n % 53)) // _Alonso del Arte_, May 03 2020
%Y Cf. A010414.
%K nonn,fini,full,easy
%O 1,1
%A _N. J. A. Sloane_.