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 A291794 #14 Mar 16 2019 15:13:47 %S A291794 5,15,15,19,0,31,85,37,31,37,55,37,0,0,91,85,31,127,31,33,37,0,37,37, %T A291794 0,73,73,163,55,19,73,157,37,73,37,37,37,163,55,37,163,37,37,85,37,0, %U A291794 0,85,37,127,91,37,37,0,37,69,19,31,163,163,87,55,0,37,0,55 %N A291794 Consider Post's tag system applied to the word (100)^n; a(n) = length of first word we see that is in the cycle, if the orbit cycles, or 0 if the orbit reaches the empty string, or -1 if the orbit is unbounded. %H A291794 Lars Blomberg, <a href="/A291794/b291794.txt">Table of n, a(n) for n = 1..6075</a> %H A291794 Peter R. J. Asveld, <a href="http://doc.utwente.nl/66184/1/1988m20.pdf">On a Post's System of Tag</a>. Bulletin of the EATCS 36 (1988), 96-102. %Y A291794 Cf. A284116 and the cross-references there. %K A291794 nonn %O A291794 1,1 %A A291794 _N. J. A. Sloane_, Sep 04 2017 %E A291794 a(33) and beyond from _Lars Blomberg_, Apr 19 2018