This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A028761 #8 Dec 24 2019 13:15:11 %S A028761 2,3,5,6,7,8,10,11,12,13,14,15,17,18,19,20,21,22,23,24,26,27,28,29,30, %T A028761 31,32,34,35,37,38,39,40,41,42,43,44,45,46,47 %N A028761 Nonsquares mod 48. %t A028761 Complement[Range[0, 47], PowerMod[Range[48], 2, 48]] (* _Alonso del Arte_, Dec 24 2019 *) %o A028761 (Scala) (0 to 47).diff((1 to 48).map(n => (n * n) % 48)) // _Alonso del Arte_, Dec 24 2019 %Y A028761 Cf. A010409. %K A028761 nonn,fini,full,easy %O A028761 1,1 %A A028761 _N. J. A. Sloane_