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 A203925 #9 Sep 04 2013 12:07:43 %S A203925 1,1,5,665,282412759265, %T A203925 1797010299914431210411850601513820123858571820477570761825 %N A203925 3^n! - 2^n!. %F A203925 a(n) = A100731(n) - A050923(n). - _Michel Marcus_, Sep 04 2013 %K A203925 nonn %O A203925 0,3 %A A203925 _Assoul Abdelkarim_, Jan 08 2012