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 A287529 #4 May 30 2017 18:18:10
%S A287529 1,5,9,11,13,18,21,23,25,29,31,36,37,41,45,48,50,52,57,59,61,65,67,72,
%T A287529 73,77,81,83,85,90,91,95,99,102,104,106,109,113,117,119,121,126,129,
%U A287529 131,133,138,140,142,146,148,153,154,158,162,165,167,169,173,175
%N A287529 Positions of 0 in A287528.
%C A287529 a(n) - a(n-1) is in {1, 2, 3, 4, 5} for n >= 1; also, 3n - a(n) is in {0, 1, 2} for n >= 1. The first 20 numbers 3n - a(n) are 2, 1, 0, 1, 2, 0, 0, 1, 2, 1, 2, 0, 2, 1, 0, 0, 1, 2, 0, 1, with 0 in positions given by A189634, 1 in positions given by A189670, and 2 in positions given by A189670.
%H A287529 Clark Kimberling, <a href="/A287529/b287529.txt">Table of n, a(n) for n = 1..10000</a>
%t A287529 s = Nest[Flatten[# /. {0->{0, 1, 2}, 1->{1, 0, 2}, 2->{2, 1, 0}}] &, {0}, 9]; (*A287528*)
%t A287529 Flatten[Position[s, 0]]; (*A287529*)
%t A287529 Flatten[Position[s, 1]]; (*A189670*)
%t A287529 Flatten[Position[s, 2]]; (*A189634*)
%Y A287529 Cf. A189670, A287528, A189634.
%K A287529 nonn,easy
%O A287529 1,2
%A A287529 _Clark Kimberling_, May 30 2017