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 A108717 #37 Jan 06 2023 20:52:15 %S A108717 11111111,11111112,11111212,11111222,11111212,11121222,11122222, %T A108717 11122221 %N A108717 An erroneous sequence. %C A108717 Old name was: A model of LQTL "possible world lines" as a balanced binary tree with four successors (S4S). Each path through the tree creates a unique "word" describing the linked nodes. Four iterations generate the sequence which is extensible. Qubits mapped to a balanced binary tree. %C A108717 For this sequence qubits have been represented as 11, 12, 21, 22, rather than the more common 00, 01, 11, 10. With the latter encoding the sequence would be 00000000, 00000001, 00000101, 00000111, 00000101, 00010111, 00011111, 00011110. %H A108717 Robert Barbour, <a href="https://www.wolframscience.com/conference/2006/presentations/barbour.html">2D Four-Color Cellular Automaton</a>, NKS 2006 Wolfram Science Conference. See presentation materials, slide 14. Note that a(4) in this sequence entry has a typo: according to the slides, it should be 11121212, representing the bit sequence 00010101. %K A108717 dead %O A108717 0,1 %A A108717 _Robert H Barbour_, Jun 20 2005