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%I #10 Jan 09 2020 03:14:00
%S 2,3,5,6,7,8,11,12,13,14,15,17,18,20,21,22,23,24,26,27,28,29,30,32,33,
%T 35,37,38,39,41,42,43,44,47,48,50,51,52,53,56,57,58,59,60,62,63,65,66,
%U 67,68,69,71,72,73,74,75,77,78,80,82,83,84,86,87,88,89
%N Nonsquares mod 90.
%t Complement[Range[0, 89], PowerMod[Range[90], 2, 90]] (* _Alonso del Arte_, Jan 03 2020 *)
%o (Scala) (0 to 89).diff((1 to 90).map(n => n * n % 90)) // _Alonso del Arte_, Jan 03 2020
%Y Cf. A010451.
%K nonn,fini,full,easy
%O 1,1
%A _N. J. A. Sloane_