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 A291067 #26 Oct 19 2017 10:46:18
%S A291067 6,5,177,178,175,174,177,178,179,180,171,550,551,548,545,550,549,610,
%T A291067 611,608,603,14864,14863,14870,14875,14876,15583,15594,15741,15744,
%U A291067 15745,15742,15745,15746,15743,114886,114887,114884,114887,114888,114885,404986
%N A291067 Largest finite number of distinct words arising in Watanabe's tag system {00, 1011} applied to a binary word w, over all starting words w of length n.
%C A291067 Watanabe's tag system {00, 1011} maps a word w over {0,1} to w', where if w begins with 0, w' is obtained by appending 00 to w and deleting the first three letters, or if w begins with 1, w' is obtained by appending 1011 to w and deleting the first three letters.
%C A291067 The empty word is included in the count.
%C A291067 Up through length 60, all starting strings either reach the empty word or enter a loop. - _Don Reble_, Sep 01 2017
%H A291067 Lars Blomberg, <a href="/A291067/b291067.txt">Table of n, a(n) for n = 1..50</a>
%H A291067 Shigeru Watanabe, <a href="/A284116/a284116.pdf">Periodicity of Post's normal process of tag</a>, in Jerome Fox, ed., Proceedings of Symposium on Mathematical Theory of Automata, New York, April 1962, Polytechnic Press, Polytechnic Institute of Brooklyn, 1963, pp. 83-99. [Annotated scanned copy]
%H A291067 N. J. A. Sloane, <a href="/A291067/a291067.txt">Maple programs that compute first 7 terms for each of A284116, A291067, A291068, A291069</a>
%e A291067 Examples of strings that achieve these records: "1", "10", "100", "0001", "10010", "100000", "1000000".
%e A291067 For example, at length 3, the trajectory of 100 begins 100, 1011, 11011, 111011, 0111011, 101100, 1001011, 10111011, 110111011, 1110111011, 01110111011, 1011101100, 11011001011, ..., and goes for 177 steps before a terms is repeated (at the 178-th step). So a(3) = 177. See A291075 for the full trajectory.
%p A291067 See link.
%Y A291067 For the 3-shift tag systems {00,1101}, {00, 1011}, {00, 1110}, {00, 0111} see A284116, A291067, A291068, A291069 respectively (as well as the cross-referenced entries mentioned there).
%Y A291067 Cf. A291072, A291075, A291780, A291781.
%K A291067 nonn
%O A291067 1,1
%A A291067 _N. J. A. Sloane_, Aug 18 2017
%E A291067 a(8)-(42) from _Lars Blomberg_, Sep 16 2017