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 A053550 #6 Mar 30 2012 16:48:45 %S A053550 1,2,-4,72,-2168,114864,-10671216,1787642272,-557621854080, %T A053550 332091938264960,-383877081387120640,870132605833456937472, %U A053550 -3891989736269204588784384,34485850497928703119235323904,-606809291874393995479640098992128 %N A053550 Reversion of [1,2,12,152,3640,...] (A053549). %H A053550 <a href="/index/Res#revert">Index entries for reversions of series</a> %K A053550 sign %O A053550 1,2 %A A053550 _N. J. A. Sloane_, Jan 16 2000