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 A036580 #26 Jul 21 2025 21:41:30
%S A036580 0,1,2,0,2,1,0,1,2,1,0,2,0,1,2,0,2,1,0,2,0,1,2,1,0,1,2,0,2,1,0,1,2,1,
%T A036580 0,2,0,1,2,1,0,1,2,0,2,1,0,2,0,1,2,0,2,1,0,1,2,1,0,2,0,1,2,0,2,1,0,2,
%U A036580 0,1,2,1,0,1,2,0,2,1,0,2,0,1,2,0,2,1,0,1,2,1,0,2,0,1,2,1,0,1,2
%N A036580 Ternary Thue-Morse sequence: closed under a->abc, b->ac, c->b.
%C A036580 0 is a, 1 is b and 2 is c. - _Robert G. Wilson v_, Jul 30 2018
%D A036580 M. Lothaire, Combinatorics on Words. Addison-Wesley, Reading, MA, 1983, p. 26.
%H A036580 Paolo Xausa, <a href="/A036580/b036580.txt">Table of n, a(n) for n = 0..10000</a>
%H A036580 Marko Milosevic and Narad Rampersad, <a href="https://arxiv.org/abs/2007.03557">Squarefree words with interior disposable factors</a>, arXiv:2007.03557 [math.CO], 2020.
%H A036580 Michaël Rao, Michel Rigo, and Pavel Salimov, <a href="https://arxiv.org/abs/1310.4743">Avoiding 2-binomial squares and cubes</a>, arXiv:1310.4743 [cs.FL], 2013.
%H A036580 Michaël Rao, Michel Rigo, and Pavel Salimov, <a href="https://doi.org/10.1016/j.tcs.2015.01.029">Avoiding 2-binomial squares and cubes</a>, Theoretical Computer Science, Volume 572, 23 March 2015, Pages 83-91.
%t A036580 Nest[Flatten[# /. {0 -> {0, 1, 2}, 1 -> {0, 2}, 2 -> {1}}] &, {1}, 7] // Most (* _Robert G. Wilson v_, Jul 30 2018, corrected by _Paolo Xausa_, Jul 21 2025 *)
%t A036580 1 - Differences[ThueMorse[Range[0,100]]] (* _Paolo Xausa_, Jul 21 2025 *)
%Y A036580 A007413(n+1) - 1.
%Y A036580 See A036577 for another version.
%K A036580 nonn
%O A036580 0,3
%A A036580 _N. J. A. Sloane_