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arXiv · 1904.08187

Circularly squarefree words and unbordered conjugates: a new approach

Trevor Clokie·Daniel Gabric·Jeffrey Shallit
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Abstract

Using a new approach based on automatic sequences, logic, and a decision procedure, we reprove some old theorems about circularly squarefree words and unbordered conjugates in a new and simpler way. Furthermore, we prove three new results about unbordered conjugates: we complete the classification, due to Harju and Nowotka, of binary words with the maximum number of unbordered conjugates; we prove that for every possible number, up to the maximum, there exists a word having that number of unbordered conjugates, and finally, we determine the expected number of unbordered conjugates in a random word.

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Trevor Clokie, Daniel Gabric, Jeffrey Shallit. 2019-04-17. Circularly squarefree words and unbordered conjugates: a new approach. https://arxiv.org/abs/1904.08187

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