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%I #15 Apr 28 2020 09:21:56
%S 2,11,212,11211,21211212,1121121211211,212112121121121211212,
%T 1121121211211212112121121121211211,
%U 2121121211211212112121121121211211212112121121121211212,11211212112112121121211211212112112121121211211212112121121121211211212112121121121211211
%N List of singular subwords (or factors) of the Fibonacci word A003842.
%C Complementing the first and last digits of each term gives (essentially) A214216.
%H Kalle Saari, <a href="http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.113.992">Periods of factors of the Fibonacci word</a>, Department of Mathematics and Turku Centre for Computer Science, University of Turku, 2001 4 Turku, Finland.
%H Kalle Saari, <a href="https://www.semanticscholar.org/paper/PERIODS-OF-FACTORS-OF-THE-FIBONACCI-WORD-KALLE-Saari/226ad5ee4e916bbddb5775d36d4d126074ca1c27">Periods of factors of the Fibonacci word</a>, in Proceedings of the Sixth International Conference on Words (WORDS’07). Institut de Mathématiques de Luminy (2007) 273-279.
%H Zhi-Xiong Wen and Zhi-Ying Wen, <a href="https://doi.org/10.1006/eujc.1994.1060">Some properties of the singular words of the Fibonacci word</a>, European J. Combin. 15 (1994), 587-598.
%F a(0)=2, a(1)=11, a(2)=212; thereafter a(n)=the concatenation of a(n-2), a(n-3), and a(n-2). [clarified by _Harvey P. Dale_, May 24 2018]
%t nxt[{a_,b_,c_}]:={b,c,FromDigits[Join[Flatten[IntegerDigits/@{b,a,b}]]]}; NestList[nxt,{2,11,212},10][[All,1]] (* _Harvey P. Dale_, May 24 2018 *)
%Y Cf. A003842, A214216.
%K nonn
%O 1,1
%A _N. J. A. Sloane_, Jul 10 2012
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