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 A049431 #10 Jun 01 2025 22:40:20 %S A049431 1,1,6,36,246,2046,19716,209616,2441916,31050396,425883816,6244077456 %N A049431 Duplicate of A049428. %K A049431 dead %O A049431 0,3