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 A287522 #5 May 30 2017 18:17:33
%S A287522 2,4,7,10,14,16,19,22,26,28,32,34,38,40,43,46,49,53,55,59,61,64,67,71,
%T A287522 74,76,79,82,86,88,92,94,97,100,103,107,110,112,115,118,122,124,127,
%U A287522 130,134,136,140,142,145,148,152,155,157,160,163,167,169,173,175
%N A287522 Positions of 1 in A287520.
%C A287522 a(n) - a(n-1) is in {2, 3, 4} for n >= 1; also, 3n - a(n) is in {1, 2} for n >= 1. The first 20 numbers 3n - a(n) are 1, 2, 2, 2, 1, 2, 2, 2, 1, 2, 1, 2, 1, 2, 2, 2, 2, 1, 2, 1, with 1 in positions given by A287521.
%H A287522 Clark Kimberling, <a href="/A287522/b287522.txt">Table of n, a(n) for n = 1..10000</a>
%t A287522 s = Nest[Flatten[# /. {0->{0, 1, 2}, 1->{1, 0, 2}, 2->{1, 2, 0}}] &, {0}, 9]; (*A287520*)
%t A287522 Flatten[Position[s, 0]]; (*A287521*)
%t A287522 Flatten[Position[s, 1]]; (*A287522*)
%t A287522 Flatten[Position[s, 2]]; (*A189630*)
%Y A287522 Cf. A287520, A287521, A189630.
%K A287522 nonn,easy
%O A287522 1,1
%A A287522 _Clark Kimberling_, May 30 2017