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 A138228 #5 Mar 30 2012 18:51:57 %S A138228 1,4,21,22,23,24,25,26,27,28,29,30,5,6,7,8,9,2 %N A138228 Atomic numbers at the top of the 18 groups of the Mendeleyev-Seaborg table A138724. %C A138228 This refers to the following 18 elements at the top of their groups: H, Be, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, B, C, N, O, F, He. %Y A138228 Cf. A138718, A135559. %K A138228 nonn,fini,full,less %O A138228 0,2 %A A138228 _Paul Curtz_, May 05 2008