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 A103269 #43 Jan 05 2025 19:51:38
%S A103269 1,12,1213,1213121,1213121121312,121312112131212131211213,
%T A103269 12131211213121213121121312131211213121213121,
%U A103269 121312112131212131211213121312112131212131211213121121312121312112131213121121312
%N A103269 Apply the tribonacci morphism 1 -> {1, 2}, 2 -> {1, 3}, 3 -> {1} n times to 1, and concatenate the resulting string.
%C A103269 The number of letters in the n-th iteration is tribonacci(n+3) (that is, A000073(n+3)).
%H A103269 N. J. A. Sloane, <a href="/A103269/b103269.txt">Table of n, a(n) for n = 0..10</a> (shortened by _N. J. A. Sloane_, Jan 18 2019)
%H A103269 Elena Barcucci, Luc Belanger and Srecko Brlek, <a href="https://web.archive.org/web/2024*/https://www.fq.math.ca/Papers1/42-4/quartbarcucci04_2004.pdf">On tribonacci sequences</a>, Fib. Q., 42 (2004), 314-320. See T on page 315.
%H A103269 Julien Cassaigne, Sebastien Ferenczi, and Luca Q. Zamboni, <a href="http://www.numdam.org/item?id=AIF_2000__50_4_1265_0">Imbalances in Arnoux-Rauzy sequences</a>, Annales de l'institut Fourier, 50 (2000), 1265-1276.
%H A103269 David Damanik and Luca Q. Zamboni, <a href="http://arxiv.org/abs/math/0208137">Arnoux-Rauzy Subshifts: Linear Recurrence, Powers and Palindromes</a>, arXiv:math/0208137 [math.CO], 2002.
%H A103269 C. Holton and L. Q. Zamboni, <a href="https://citeseerx.ist.psu.edu/pdf/c87e53604abd732cab6eaac7034160636ea39aa3">Directed Graphs and Substitutions</a>, Theory Comput. Systems, 34 (2001) 545-564
%H A103269 S. Ito and M. Kimura, <a href="http://dx.doi.org/10.1007/BF03167147">On Rauzy fractal</a>, Japan J. Indust. Appl. Math. 8 (1991) 461-486.
%H A103269 A. Messaoudi, <a href="http://dx.doi.org/10.5802/jtnb.223">Propriétes arithmétiques et dynamiques du fractal de Rauzy</a>, J. Th. Nombres Bordeaux, 10 (1998) 195-224.
%H A103269 Gérard Rauzy, <a href="http://www.numdam.org/item?id=BSMF_1982__110__147_0">Nombres algébriques et substitutions</a>, Bull. Soc. Math. France, 110 (1982), 147-178.
%H A103269 Bo Tan and Zhi-Ying Wen, <a href="http://dx.doi.org/10.1016/j.ejc.2006.07.007">Some properties of the Tribonacci sequence</a>, European Journal of Combinatorics, 28 (2007) 1703-1719. See A_n.
%H A103269 <a href="/index/Fi#FIXEDPOINTS">Index entries for sequences that are fixed points of mappings</a>
%t A103269 FromDigits /@ NestList[ Flatten[ # /. {1 -> {1, 2}, 2 -> {1, 3}, 3 -> 1}] &, {1}, 7]
%t A103269 (* Second program: *)
%t A103269 FromDigits /@ SubstitutionSystem[{1 -> {1, 2}, 2 -> {1, 3}, 3 -> {1}}, {1}, 7] (* _Jean-François Alcover_, Nov 12 2018 *)
%Y A103269 A092782 is limit of these strings.
%Y A103269 Cf. A000073, A106748, A106749, A003842, A106750, A092782, A317196.
%K A103269 nonn
%O A103269 0,2
%A A103269 _Jonathan Vos Post_ and _Robert G. Wilson v_, May 16 2005
%E A103269 Definition edited by _N. J. A. Sloane_, Aug 06 2018