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 A287568 #4 May 31 2017 21:24:36
%S A287568 4,6,9,15,17,23,28,30,35,40,42,45,50,53,59,64,67,72,74,77,82,85,91,96,
%T A287568 100,102,105,111,113,119,124,126,130,133,139,144,148,150,153,159,161,
%U A287568 167,172,174,179,184,186,189,193,199,204,206,211,216,218,221,226
%N A287568 Positions of 1 in A287566.
%C A287568 a(n) - a(n-1) is in {1,2,3,4,5,6} for n >= 1; also, 4n - a(n) is in {0,1,2,3} for n >= 1. The first 20 numbers 4n - a(n) are 0, 2, 3, 1, 3, 1, 0, 2, 1, 0, 2, 3, 2, 3, 1, 0, 1, 0, 2, 3, with
%C A287568 0 in positions given by A287567,
%C A287568 1 in positions given by A287568,
%C A287568 2 in positions given by A287569,
%C A287568 3 in positions given by A287570.
%H A287568 Clark Kimberling, <a href="/A287568/b287568.txt">Table of n, a(n) for n = 1..10000</a>
%F A287568 a(n) = 4n - A287566(n) for n >= 1.
%t A287568 s = Nest[Flatten[# /. {0 -> {0, 2, 3, 1}, 1 -> {2, 3, 2, 0}, 2 -> {3, 1, 0, 2}, 3 -> {1, 0, 2, 3}}] &, {0}, 9]; (* A287566 *)
%t A287568 Flatten[Position[s, 0]]; (* A287567 *)
%t A287568 Flatten[Position[s, 1]]; (* A287568 *)
%t A287568 Flatten[Position[s, 2]]; (* A287569 *)
%t A287568 Flatten[Position[s, 3]]; (* A287570 *)
%Y A287568 Cf. A287566, A287567, A287569, A287570.
%K A287568 nonn,easy
%O A287568 1,1
%A A287568 _Clark Kimberling_, May 31 2017