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 A140813 #21 Feb 12 2023 15:16:42 %S A140813 4,12,24,360,360,2520,5040,5040,5040,55440,55440,3603600,10810800, %T A140813 10810800,21621600,367567200,367567200,6983776800,6983776800, %U A140813 6983776800,6983776800,160626866400,160626866400,1124388064800,1124388064800 %N A140813 Duplicate of A073841. %K A140813 dead %O A140813 2,1