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 A174206 #8 Jan 04 2013 16:03:55 %S A174206 0,1,1,1,0,0,1,1,1,1,0,0,0,1,1,0,1,1,0,1,0,1,1,1,1,1,0,0,0,0,1,0,1,0, %T A174206 1,1,0,0,1,0,1,1,0,1,1,1,0,0,1,0,1,1,0,1,1,1,1,0,1,0,1,1,1,1,1 %N A174206 Write natural numbers in base 2 as a stream of digits. Moving left to right, delete even occurrences of digit 0 and 1. %e A174206 Numbers in base 2: 0, 1, 10, 11, 100, 101, 110, 111, 1000..... Stream of digits: 0110111001011101111000 Delete even occurrences of 0(replaced by ~): 011~1110~10111~11110~0 Delete even occurrences of 1(replaced by ~): 01~~1~10~~01~1~~1~10~0 Left digits: 0, 1, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0,.... %Y A174206 A174203-A174205, A174207-A174210 %K A174206 easy,nonn,base,uned %O A174206 0,1 %A A174206 _Paolo P. Lava_ and _Giorgio Balzarotti_, Mar 15 2010