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 A287553 #4 May 31 2017 15:46:49
%S A287553 2,5,12,15,17,24,27,30,36,39,42,45,51,54,57,64,65,72,75,78,84,87,90,
%T A287553 93,99,102,105,112,114,117,124,127,132,135,138,141,147,150,153,160,
%U A287553 162,165,172,175,177,184,187,190,195,198,201,208,210,213,220,223,225
%N A287553 Positions of 1 in A053839.
%C A287553 a(n) - a(n-1) is in {1,2,3,4,5,6,7} for n >= 1; also, 4n - a(n) is in {0,1,2,3} for n >= 1. The first 20 numbers 4n - a(n) are 2, 3, 0, 1, 3, 0, 1, 2, 0, 1, 2, 3, 1, 2, 3, 0, 3, 0, 1, 2, with
%C A287553 0 in positions given by A287554,
%C A287553 1 in positions given by A287555,
%C A287553 2 in positions given by A287552,
%C A287553 3 in positions given by A287553.
%H A287553 Clark Kimberling, <a href="/A287553/b287553.txt">Table of n, a(n) for n = 1..10000</a>
%t A287553 s = Nest[Flatten[# /. {0 -> {0, 1, 2, 3}, 1 -> {1, 2, 3, 0}, 2 -> {2, 3, 0, 1}, 3 -> {3, 0, 1, 2}}] &, {0}, 9]; (* A053839 *)
%t A287553 Flatten[Position[s, 0]]; (* A287552 *)
%t A287553 Flatten[Position[s, 1]]; (* A287553 *)
%t A287553 Flatten[Position[s, 2]]; (* A287554 *)
%t A287553 Flatten[Position[s, 3]]; (* A287555 *)
%Y A287553 Cf. A053839, A287552, A287554, A287555.
%K A287553 nonn,easy
%O A287553 1,1
%A A287553 _Clark Kimberling_, May 31 2017