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 A317196 #5 Aug 05 2018 10:04:32
%S A317196 2,13,121,121312,12131211213,12131211213121213121,
%T A317196 1213121121312121312112131213121121312,
%U A317196 12131211213121213121121312131211213121213121121312112131212131211213
%N A317196 a(n) = concatenation of n-th stage of the trajectory of 2 under the tribonacci morphism 1 -> {1, 2}, 2 -> {1, 3}, 3 -> {1}.
%C A317196 a(n) is the concatenation of A103269(n-1) and A103269(n-2) for n >= 2.
%H A317196 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 B_n.
%Y A317196 Cf. A103269.
%K A317196 nonn
%O A317196 0,1
%A A317196 _N. J. A. Sloane_, Aug 05 2018