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 A099933 #5 Jun 05 2023 11:11:42 %S A099933 1,2,11,110,1555,28248,626219,16383796,494052001,16870035070, %T A099933 643387631279,27105962133498,1250204513874499,62655598615243340, %U A099933 3390311968553510615,196993431796981792712,12233255754813946704001,808560048188371962179034,56672826844096496885966099 %N A099933 Main diagonal of array A007754. %F A099933 a(n) = A007754(n,n). %Y A099933 Cf. A007754. %K A099933 nonn %O A099933 0,2 %A A099933 _Ralf Stephan_, Nov 06 2004