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 A162414 #5 Nov 21 2013 12:49:39 %S A162414 3,27,443426488243037769948249630619149892803 %N A162414 a(0)=3 and a(n+1)=a(n)^a(n). %C A162414 If the initial term is 2 the sequence is 2, 4, 256, 256^256, ... %t A162414 NestList[#^#&,3,2] (* _Harvey P. Dale_, Nov 06 2011 *) %Y A162414 Cf. A000312. %K A162414 bref,nonn %O A162414 0,1 %A A162414 _Benoit Jubin_, Jul 02 2009