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 A287333 #4 May 23 2017 21:00:48
%S A287333 1,3,9,11,13,19,25,31,35,39,41,43,49,51,53,59,61,63,69,75,81,85,89,91,
%T A287333 93,99,105,111,115,119,121,123,129,135,141,145,149,151,153,159,163,
%U A287333 167,169,171,177,181,185,187,189,195,197,199,205,207,209,215,221
%N A287333 Positions of 1 in A287331.
%H A287333 Clark Kimberling, <a href="/A287333/b287333.txt">Table of n, a(n) for n = 1..10000</a>
%t A287333 s = Nest[Flatten[# /. {0 -> {1, 0}, 1 -> {2, 2}, 2 -> 0}] &, {0}, 10] (* A287331 *)
%t A287333 Flatten[Position[s, 0]] (* A287332 *)
%t A287333 Flatten[Position[s, 1]] (* A287333 *)
%t A287333 Flatten[Position[s, 2]] (* A287334 *)
%Y A287333 Cf. A287331, A287332, A287334.
%K A287333 nonn,easy
%O A287333 1,2
%A A287333 _Clark Kimberling_, May 23 2017