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 A137575 #11 May 21 2025 15:45:34 %S A137575 1,2,8,8,8,8,8,8,8,8,18,18,18,18,18,18,18,18,18,18,18,18,18,18,18,18, %T A137575 18,18,32,32,32,32,32,32,32,32,32,32,32,32,32,32,32,32,32,32,32,32,32, %U A137575 32,32,32,32,32,32,32,32,32,32,32 %N A137575 Successive structures central number of Seaborg's periodic table of the elements (extended to 32 columns) for odd rows. %C A137575 Note that 60 is half of 120, the number of elements in Charles Janet's 32-column table. This implies the existence of element 119, Ununennium (structure last number is 9) and element 120, Unbinilium (10). Structure of element 117, Ununseptium, is unknown. %F A137575 60 terms: 2 (2's) (1,2) + 8 (8's) + 18 (18's) + 32 (32's). %Y A137575 Cf. A134984, 118 elements. %K A137575 nonn,fini,full,uned %O A137575 1,2 %A A137575 _Paul Curtz_, Apr 26 2008