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 A317956 #8 Aug 22 2018 20:35:38
%S A317956 1,121,1211121,121112121211121,1211121212111211121112121211121,
%T A317956 121112121211121112111212121112121211121212111211121112121211121
%N A317956 Apply the morphism X -> XYX, where Y=1 if X contains an odd number of 1's, otherwise Y = 2 n times to 1, and concatenate the resulting string.
%D A317956 Karamanos, Kostas. "From symbolic dynamics to a digital approach." International Journal of Bifurcation and Chaos 11.06 (2001): 1683-1694. (Full version. See p. 1685)
%D A317956 Karamanos, K. (2000). From symbolic dynamics to a digital approach: chaos and transcendence. In Michel Planat (Ed.), Noise, Oscillators and Algebraic Randomness (Lecture Notes in Physics, pp. 357-371). Springer, Berlin, Heidelberg. (Short version. See p. 359)
%Y A317956 The limit of the terms is A056832.
%Y A317956 A317957 is the same sequence over the alphabet {1,0}.
%K A317956 nonn
%O A317956 0,2
%A A317956 _N. J. A. Sloane_, Aug 22 2018