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 A005556 #20 Sep 08 2022 08:44:33
%S A005556 1,4,5,7,8,11
%N A005556 Exponents m_i associated with Weyl group W(E6).
%D A005556 H. S. M. Coxeter and W. O. J. Moser, Generators and Relations for Discrete Groups, 4th ed., Springer-Verlag, NY, reprinted 1984, p. 141.
%H A005556 R. K. Guy, <a href="/A005555/a005555.pdf">Letter to N. J. A. Sloane, May 1990</a>
%o A005556 (Magma) Exponents(RootDatum("E6")); // Sergei Haller (sergei(AT)sergei-haller.de), Dec 21 2006
%K A005556 nonn,fini,full
%O A005556 1,2
%A A005556 _N. J. A. Sloane_
%E A005556 Edited by _N. J. A. Sloane_, May 13 2008