English

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

Combinatorics 2016-10-03 v2 Discrete Mathematics Formal Languages and Automata Theory

Abstract

A long standing question asks whether Z\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 Z\mathbb{Z} avoiding two consecutive blocks of same size and same sum or not. Cassaigne \emph{et al.} [2014] showed that Z\mathbb{Z} is not uniformly 3-repetitive. We show that Z2\mathbb{Z}^2 is not uniformly 2-repetitive. Moreover, this problem is related to a question from M\"akel\"a in combinatorics on words and we answer to a weak version of it.

Cite

@article{arxiv.1511.05875,
  title  = {Avoiding two consecutive blocks of same size and same sum over $\mathbb{Z}^2$},
  author = {Michaël Rao and Matthieu Rosenfeld},
  journal= {arXiv preprint arXiv:1511.05875},
  year   = {2016}
}
R2 v1 2026-06-22T11:48:38.144Z