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 A287074 #4 May 21 2017 14:34:57
%S A287074 2,4,7,9,12,14,16,18,21,23,25,28,30,32,34,37,39,41,44,46,49,51,53,56,
%T A287074 58,60,62,65,67,69,72,74,77,79,81,83,86,88,90,93,95,98,100,102,105,
%U A287074 107,109,111,114,116,118,121,123,126,128,130,132,135,137,139,142
%N A287074 Positions of 1 in A287072.
%H A287074 Clark Kimberling, <a href="/A287074/b287074.txt">Table of n, a(n) for n = 1..10000</a>
%t A287074 s = Nest[Flatten[# /. {0 -> {0, 1}, 1 -> {2, 1}, 2 -> 0}] &, {0}, 10] (* A287072 *)
%t A287074 Flatten[Position[s, 0]] (* A287073 *)
%t A287074 Flatten[Position[s, 1]] (* A287074 *)
%t A287074 Flatten[Position[s, 2]] (* A287075 *)
%Y A287074 Cf. A287072, A287073, A287075.
%K A287074 nonn,easy
%O A287074 1,1
%A A287074 _Clark Kimberling_, May 21 2017