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 A245553 #17 Oct 02 2016 10:26:31
%S A245553 1,2,3,2,3,3,1,2,3,3,1,3,1,1,2,3,2,3,3,1,3,1,1,2,3,3,1,1,2,3,1,2,3,2,
%T A245553 3,3,1,2,3,3,1,3,1,1,2,3,3,1,1,2,3,1,2,3,2,3,3,1,3,1,1,2,3,1,2,3,2,3,
%U A245553 3,1,1,2,3,2,3,3,1,2,3,3,1,3,1,1,2,3
%N A245553 A Rauzy fractal sequence: trajectory of 1 under morphism 1 -> 2,3; 2 -> 3; 3 -> 1.
%H A245553 P. Arnoux and E. Harriss, <a href="http://www.ams.org/notices/201407/rnoti-p768.pdf">What is a Rauzy Fractal?</a>, Notices Amer. Math. Soc., 61 (No. 7, 2014), 768-770, also p. 704 and front cover.
%H A245553 Marcy Barge and Jaroslaw Kwapisz, <a href="http://www.jstor.org/stable/40068030">Geometric theory of unimodular Pisot substitutions</a>, Amer. J. Math. 128 (2006), no. 5, 1219--1282. MR2262174 (2007m:37039). See Fig. 18.1.
%H A245553 <a href="/index/Fi#FIXEDPOINTS">Index entries for sequences that are fixed points of mappings</a>
%t A245553 Nest[ Function[ l, {Flatten[(l /. {1 -> {2, 3}, 2 -> {3}, 3 -> {1}})] }], {1}, 15]
%Y A245553 Cf. A092782, A245554, A105083.
%K A245553 nonn
%O A245553 1,2
%A A245553 _N. J. A. Sloane_, Aug 03 2014