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 A010380 #20 Dec 18 2019 21:51:53 %S A010380 0,1,4,7,9,10,13,16 %N A010380 Squares mod 18. %t A010380 Union[PowerMod[Range[18], 2, 18]] (* _Alonso del Arte_, Dec 18 2019 *) %o A010380 (Sage) [quadratic_residues(18)] # _Zerinvary Lajos_, May 24 2009 %o A010380 (Scala) (1 to 18).map(n => (n * n) % 18).toSet.toSeq.sorted // _Alonso del Arte_, Dec 18 2019 %Y A010380 Row 18 of A096008. %Y A010380 Cf. A028731. %K A010380 nonn,fini,full %O A010380 1,3 %A A010380 _N. J. A. Sloane_