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 A287437 #12 Jun 14 2017 11:22:14
%S A287437 3,5,7,11,13,18,19,24,26,29,31,36,37,42,44,48,50,52,55,60,62,66,68,70,
%T A287437 74,76,81,83,85,90,91,96,98,102,104,106,109,114,116,120,122,124,128,
%U A287437 130,135,138,140,142,146,148,153,154,159,161,163,168,170,174,176
%N A287437 Positions of 2 in A053838.
%C A287437 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.
%C A287437 Does this differ from A026603? - _R. J. Mathar_, Jun 14 2017
%H A287437 Clark Kimberling, <a href="/A287437/b287437.txt">Table of n, a(n) for n = 1..10000</a>
%F A287437 a(n) + A053838(n-1) = 3n.
%t A287437 s = Nest[Flatten[# /. {0->{0, 1, 2}, 1->{1, 2, 0}, 2->{2, 0, 1}}] &, {0}, 9]; (*A053838*)
%t A287437 Flatten[Position[s, 0]]; (*A287435*)
%t A287437 Flatten[Position[s, 1]]; (*A287436*)
%t A287437 Flatten[Position[s, 2]]; (*A287437*)
%Y A287437 Cf. A053838, A287435, A287436.
%K A287437 nonn,easy
%O A287437 1,1
%A A287437 _Clark Kimberling_, May 26 2017
%E A287437 The definition refers to a different offset in A053838. - _R. J. Mathar_, May 30 2017