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 A214339 #12 Nov 08 2013 23:36:29 %S A214339 2,1,2,1,2,1,0,2,1,2,1,0,2,1,1,2,1,2,1,0,2,1,1,2,1,0,0,2,1,2,1,0,2,1, %T A214339 1,2,1,0,0,2,1,0,1,2,1,2,1,0,2,1,1,2,1,0,0,2,1,0,1,2,1,1,0,2,1,2,1,0, %U A214339 2,1,1,2,1,0,0,2,1,0,1,2,1,1,0,2,1,1,1,2,1,2,1,0,2,1,1,2,1,0,0,2,1,0,1,2,1,1,0,2,1,1,1,2,1,0,0,0,2,1,2,1,0,2,1,1,2,1 %N A214339 Let S_m = concatenation of words 2(1)_2, 2(2)_2, 2(3)_2, ..., 2(m)_2, where (i)_2 denotes the binary expansion of i; then sequence is S_1, S_2, S_3, ... %H A214339 Daniel Goc, Luke Schaeffer and Jeffrey Shallit, <a href="http://arxiv.org/abs/1206.5352">The Subword Complexity of k-Automatic Sequences is k-Synchronized</a>, arXiv 1206.5352, Jun 28 2012. See Example 3. %e A214339 We have %e A214339 S_1 = 2 1, %e A214339 S_2 = 2 1, 2 1 0, %e A214339 S_3 = 2 1, 2 1 0, 2 1 1, %e A214339 S_4 = 2 1, 2 1 0, 2 1 1, 2 1 0 0, %e A214339 ... so the sequence begins %e A214339 2 1, 2 1 2 1 0, 2 1 2 1 0 2 1 1, 2 1 2 1 0 2 1 1 2 1 0 0, ... %K A214339 nonn %O A214339 1,1 %A A214339 _N. J. A. Sloane_, Jul 28 2012