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 A010415 #16 Dec 27 2019 16:21:23 %S A010415 0,1,4,7,9,10,13,16,19,22,25,27,28,31,34,36,37,40,43,46,49,52 %N A010415 Squares mod 54. %t A010415 Union[PowerMod[Range[54], 2, 54]] (* _Alonso del Arte_, Dec 27 2019 *) %o A010415 (Sage) [quadratic_residues(54)] # _Zerinvary Lajos_, May 24 2009 %o A010415 (Scala) (1 to 54).map(n => (n * n) % 54).toSet.toSeq.sorted // _Alonso del Arte_, Dec 27 2019 %Y A010415 Cf. A028767. %K A010415 nonn,fini,full,easy %O A010415 1,3 %A A010415 _N. J. A. Sloane_