Abstract
We consider shuffles of words. It is first shown that there are infinite square-free words w over a four-letter alphabet such that w is a perfect shuffle of two square-free words u and v. Then we show that there exists an infinite square-free word u on three letters such that u can be shuffled with itself to produce another infinite square-free word. The proof of the latter result is constructive on finite factors, and it relies on a computer program for checking square-freeness of longer words.
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Harju, T. (2013). A Note on Square-Free Shuffles of Words. In: Karhumäki, J., Lepistö, A., Zamboni, L. (eds) Combinatorics on Words. Lecture Notes in Computer Science, vol 8079. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-40579-2_17
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DOI: https://doi.org/10.1007/978-3-642-40579-2_17
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