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 A291075 #17 Dec 12 2023 13:42:30
%S A291075 211,2122,22122,222122,1222122,212211,2112122,21222122,221222122,
%T A291075 2221222122,12221222122,2122212211,22122112122,221121222122,
%U A291075 1212221222122,222122212211,1222122112122,212211212211,2112122112122,21221121222122,211212221222122,2122212221222122
%N A291075 Trajectory of the word "211" under the Watanabe tag system {11, 2122} described in A291067 (adapted to the alphabet {1,2}).
%C A291075 At step 172, enters a cycle of length 6.
%C A291075 Working this out by hand, one is convinced that it is going to blow up. The cycle after reaching 11111121222122212211111121222122212211111121222122212211
%C A291075 comes as a surprise!
%H A291075 N. J. A. Sloane, <a href="/A291075/b291075.txt">Table of n, a(n) for n = 1..200</a>
%Y A291075 Cf. A291067, A291072.
%K A291075 nonn
%O A291075 1,1
%A A291075 _N. J. A. Sloane_, Aug 18 2017