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 A236320 #15 Aug 14 2015 23:11:23 %S A236320 0,0,0,0,1,11,69,677,6709 %N A236320 Conjectured number of Sierpiński numbers less than 10^n. %H A236320 Wikipedia, <a href="http://en.wikipedia.org/wiki/Sierpinski_number">Sierpinski number</a> %F A236320 a(n) ~ A236321(n). %Y A236320 Cf. A076336, A236321, A237880. %K A236320 nonn,more %O A236320 1,6 %A A236320 _Arkadiusz Wesolowski_, Jan 22 2014