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 A012194 #4 Feb 24 2012 12:50:43 %S A012194 1,1,1,0,-3,4,69,136,-1159,1744,115081,652864,-3250827,16365504, %T A012194 1156388557,12624963456,-12628752143,910310355200,42394317198097, %U A012194 735663001262080,2830775181039853,125940707707991040 %N A012194 exp(arctan(arcsin(x)))=1+x+1/2!*x^2-3/4!*x^4+4/5!*x^5+69/6!*x^6... %K A012194 sign %O A012194 0,5 %A A012194 Patrick Demichel (patrick.demichel(AT)hp.com)