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 A287161 #4 May 22 2017 12:23:48
%S A287161 1,7,11,13,14,20,22,23,27,28,31,37,41,43,44,48,49,52,58,60,61,64,70,
%T A287161 71,77,81,83,84,90,92,93,97,98,101,107,109,110,113,119,120,126,130,
%U A287161 132,133,137,138,141,147,148,154,158,160,161,164,170,174,176,177,183
%N A287161 Positions of 0 in A287160.
%H A287161 Clark Kimberling, <a href="/A287161/b287161.txt">Table of n, a(n) for n = 1..10000</a>
%t A287161 s = Nest[Flatten[# /. {0 -> {1, 0}, 1 -> {2, 1}, 2 -> 0}] &, {0}, 9] (* A287160 *)
%t A287161 Flatten[Position[s, 0]] (* A287161 *)
%t A287161 Flatten[Position[s, 1]] (* A287162 *)
%t A287161 Flatten[Position[s, 2]] (* A287163 *)
%Y A287161 Cf. A287160, A287162, A287163.
%K A287161 nonn,easy
%O A287161 1,2
%A A287161 _Clark Kimberling_, May 22 2017