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 A143248 #16 Jul 24 2016 20:21:29 %S A143248 0,12,144,2880,86400,3628800,203212800,14631321600,1316818944000, %T A143248 144850083840000,19120211066880000,2982752926433280000, %U A143248 542861032610856960000,114000816848279961600000 %N A143248 Erroneous version of A010790. %K A143248 dead %O A143248 1,2