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 A108042 #3 Mar 30 2012 16:50:16 %S A108042 1,1,2,7,42,443,8473,302615,20667866,2746018153,717844380672, %T A108042 371804591916373,383132488758103018,787329849067164994524, %U A108042 3230799141690805716086494,26492531918877575209777027523,434278730987058524389013641832164,14234353051803016490396754839888900505 %N A108042 Leading diagonal of triangle A108041. %K A108042 nonn %O A108042 0,3 %A A108042 _N. J. A. Sloane_, Jun 01 2005