%I #9 Dec 26 2019 05:09:45
%S 2,3,5,6,7,8,10,11,14,15,18,19,20,21,22,23,24,26,27,28,30,31,32,33,34,
%T 35,37,38,39,41,42,43,44,45,46,47,50,51
%N Nonsquares mod 52.
%t Complement[Range[0, 51], PowerMod[Range[52], 2, 52]] (* _Alonso del Arte_, Dec 26 2019 *)
%o (Scala) (0 to 51).diff((1 to 52).map(n => (n * n) % 52)) // _Alonso del Arte_, Dec 26 2019
%Y Cf. A010413.
%K nonn,fini,full,easy
%O 1,1
%A _N. J. A. Sloane_