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 A137161 #3 Aug 24 2012 10:50:00 %S A137161 1,1,0,1,0,1,1,1,1,1,1,1,0,1,0,1,1,1,1,1,0,1,1,1,1,1,0,1,1,1,0,1,0,1, %T A137161 1,1,0,1,1,1,1,1,1,1,0,1,1,1,0,1,1,1,1,1,1,1,0,1,1,1,0,1,1,1,1,1,1,1, %U A137161 0,1,1,1,1,1,1,1,1,1,0,1,0,1,1,1,0,1,0,1,1,1,1,1,0,1,1,1,1,1,0,1,1,1,0,1,0 %N A137161 Starting at Step=0 from the sequence 1, 0, 1, 0, 1, 0, etc. (A059841) at any Step=n, with n>=1, any numbers of the previous step is inserted in the sequence any (2*n-1) numbers. %C A137161 If the sequence is regarded as the binary representation of the number 0.1101011111110...... in decimal it is 0.843596927232253.... %e A137161 Step n=0: 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, etc. %e A137161 Step n=1: 2*n-1=1 thus after any 1 number -> 1 number of Step=0 is inserted %e A137161 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, etc. %e A137161 Step n=2: 2*n-1=3 thus after any 3 numbers -> 1 number of Step=1 is inserted %e A137161 1, 1, 0, 1, 0, 1, 1, 1, 0, 0, 1, 0, 1, 0, 0, 0, 1, 1, 0, 1, 0, 1, 1, 1, 0, 0, 1, 0, 1, 0, 0, 0, 1, 1, 0, 1, 0, 1, 1, 1, 0, 0, etc. %e A137161 Step n=3: 2*n-1=5 thus after any 5 numbers -> 1 number of Step=2 is inserted %e A137161 1, 1, 0, 1, 0, 1, 1, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 0, 0, 1, 1, 0, 1, 1, 0, 1, 1, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 0, 1, 1, 0, 1, etc. %e A137161 And so on. %Y A137161 Cf. A137162, A137163. %K A137161 easy,nonn %O A137161 0,1 %A A137161 _Paolo P. Lava_ and _Giorgio Balzarotti_, Jan 25 2008, Mar 05 2008