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 A050722 #8 Aug 11 2024 14:41:32 %S A050722 3,6,66,5995,15051,15199896744769899151 %N A050722 Palindromic triangular numbers arising from A050721 and A083571. %H A050722 P. De Geest, <a href="https://www.worldofnumbers.com/subtria.htm">Subsets of palindromic triangulars</a> %Y A050722 Cf. A008509, A008510, A050721. %K A050722 nonn,base,hard %O A050722 1,1 %A A050722 _Patrick De Geest_, Sep 15 1999