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 A225186 #23 Nov 26 2020 16:51:48
%S A225186 11,22,1212,2121,121121,212212,12211221,21122112,122112122112,
%T A225186 211221211221,1221211212212112,2112122121121221,
%U A225186 122121121221122121121221,211212212112211212212112,12212112211212211221211221121221,21121221122121122112122112212112
%N A225186 Squares in the Thue-Morse word A001285.
%C A225186 A square in an infinite word w is a factor of the form uu, where u has finite length.
%C A225186 Consists of 11, 22, 121121, 212212 and their repeated images under the morphism 1 -> 12, 2 -> 21.
%C A225186 Replacing {1,2} by {0,1} gives the squares in A010060.
%H A225186 James D. Currie and Narad Rampersad, <a href="https://arxiv.org/abs/0803.1189">Infinite words containing squares at every position</a>, arXiv:0803.1189 [math.CO], 2008; or <a href="https://doi.org/10.1051/ita/2010007">also</a>, RAIRO-Theor. Inf. Appl. 44, 113-124 (2010).
%Y A225186 Cf. A001285, A020060, A225188 (square roots).
%K A225186 nonn
%O A225186 1,1
%A A225186 _N. J. A. Sloane_, May 04 2013