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 A028925 #7 Jul 08 2025 18:56:17 %S A028925 0,1,3,6,12,20,36,63,120,136 %N A028925 Maximal number of pairs of minimal vectors in an n-dimensional lattice. %D A028925 J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 15. %Y A028925 A001116 / 2. %K A028925 nonn,hard,more %O A028925 0,3 %A A028925 _N. J. A. Sloane_