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 A113879 #4 Mar 31 2012 10:21:59
%S A113879 1,2,3,5,8,17,54,67,208,1753,5042,6311
%N A113879 a(n) = 1+A113878(n).
%F A113879 Sum_{n>=1} 1/(2^a(n)) = 1/2+1/(2^2)+1/(2^3)+1/(2^5)+1/(2^8)+... = 0.910163879394531305517927948...
%Y A113879 Cf. A113824.
%K A113879 nonn
%O A113879 1,2
%A A113879 _Artur Jasinski_, Jan 27 2006
%E A113879 Simplified definition - _R. J. Mathar_, Oct 01 2009