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 A103527 #3 Mar 30 2012 16:50:11 %S A103527 2,6,70,1180591620717411303494 %N A103527 a(0) = 2; a(n+1) = 2^a(n) + a(n). %K A103527 nonn %O A103527 0,1 %A A103527 _N. J. A. Sloane_, Mar 21 2005 %E A103527 The next term is too large to include.