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 A287073 #4 May 21 2017 14:34:47
%S A287073 1,5,8,10,13,17,19,22,26,29,33,35,38,42,45,47,50,54,57,61,63,66,70,73,
%T A287073 75,78,82,84,87,91,94,96,99,103,106,110,112,115,119,122,124,127,131,
%U A287073 133,136,140,143,147,149,152,156,159,161,164,168,170,173,177,180
%N A287073 Positions of 0 in A287072.
%H A287073 Clark Kimberling, <a href="/A287073/b287073.txt">Table of n, a(n) for n = 1..10000</a>
%t A287073 s = Nest[Flatten[# /. {0 -> {0, 1}, 1 -> {2, 1}, 2 -> 0}] &, {0}, 10] (* A287072 *)
%t A287073 Flatten[Position[s, 0]] (* A287073 *)
%t A287073 Flatten[Position[s, 1]] (* A287074 *)
%t A287073 Flatten[Position[s, 2]] (* A287075 *)
%Y A287073 Cf. A287072, A287074, A287075.
%K A287073 nonn,easy
%O A287073 1,2
%A A287073 _Clark Kimberling_, May 21 2017