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 A287175 #4 May 22 2017 20:03:42
%S A287175 2,4,5,7,9,11,13,15,17,18,20,22,24,25,27,29,31,33,35,37,38,40,42,44,
%T A287175 46,48,49,51,53,55,57,59,61,62,64,66,68,70,72,74,75,77,79,81,83,85,86,
%U A287175 88,90,92,94,96,98,99,101,103,105,106,108,110,112,114,116
%N A287175 Positions of 0 in A287174.
%H A287175 Clark Kimberling, <a href="/A287175/b287175.txt">Table of n, a(n) for n = 1..10000</a>
%t A287175 s = Nest[Flatten[# /. {0 -> {1, 0}, 1 -> {2, 0}, 2 -> 0}] &, {0}, 11] (* A287174 *)
%t A287175 Flatten[Position[s, 0]] (* A287175 *)
%t A287175 Flatten[Position[s, 1]] (* A287176 *)
%t A287175 Flatten[Position[s, 2]] (* A287177 *)
%Y A287175 Cf. A287174, A287176, A287177.
%K A287175 nonn,easy
%O A287175 1,1
%A A287175 _Clark Kimberling_, May 22 2017