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arXiv · 1511.05875

Avoiding two consecutive blocks of same size and same sum over $\mathbb{Z}^2$

Michaël Rao·Matthieu Rosenfeld
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Abstract

A long standing question asks whether $\mathbb{Z}$ is uniformly 2-repetitive [Justin 1972, Pirillo and Varricchio, 1994], that is, whether there is an infinite sequence over a finite subset of $\mathbb{Z}$ avoiding two consecutive blocks of same size and same sum or not. Cassaigne \emph{et al.} [2014] showed that $\mathbb{Z}$ is not uniformly 3-repetitive. We show that $\mathbb{Z}^2$ is not uniformly 2-repetitive. Moreover, this problem is related to a question from Mäkelä in combinatorics on words and we answer to a weak version of it.

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Michaël Rao, Matthieu Rosenfeld. 2016-09-30. Avoiding two consecutive blocks of same size and same sum over $\mathbb{Z}^2$. https://arxiv.org/abs/1511.05875

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