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 A030253 #12 Feb 15 2015 10:42:18 %S A030253 1,4,1485,75503872,1017252851596875,5757133327963849592814528, %T A030253 20215881652044379995902152075055222830, %U A030253 61135717735233219050448568789931104340315383312314368 %N A030253 Number of nonisomorphic groupoids with 1 idempotent. %H A030253 <a href="/index/Gre#groupoids">Index entries for sequences related to groupoids</a> %K A030253 nonn %O A030253 1,2 %A A030253 _Christian G. Bower_, Feb 15 1998 and May 15 1998