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 A205596 #5 Mar 30 2012 17:28:44 %S A205596 2,5,8,20,44,71,107,161,242,545,818,1841,2762,6215,9323,13985,20978, %T A205596 47201,70802,159305,238958,358910,807548,1814615,2721923,4082885, %U A205596 6124328,13779557,20669336,40222412,87267041 %N A205596 Least k such that A205592(k) = 2^n. %H A205596 <a href="http://www.bmoc.maths.org/home/bmo2-2012.pdf">2011/12 British Mathematical Olympiad Round 2</a>, Problem 2. %Y A205596 Cf. A205591, A205592, A205593, A205594, A205595. %K A205596 nonn %O A205596 0,1 %A A205596 _Joseph Myers_, Jan 29 2012