Given a finite alphabet Σ and a right-infinite word w over Σ, we define the Lie complexity function L w: N→ N, whose value at n is the number of conjugacy classes (under cyclic shift) …
This collaborative volume aims at presenting and developing recent trends at the interface between the study of sequences, groups, and number theory, as the title may suggest. It is …
For a rational number r such that 1< r≤ 2, an undirected r-power is a word of the form xyx′, where the word x is nonempty, the word x′ is in {x, x R}, and we have| xyx′|/| xy|= r. The …
P Ochem, M Rosenfeld - The Electronic Journal of Combinatorics, 2021 - combinatorics.org
We characterize the formulas that are avoided by every $\alpha $-free word for some $\alpha> 1$. We show that the avoidable formulas whose fragments are of the form $ XY …
P Ochem, M Rosenfeld - International Conference on Developments in …, 2016 - Springer
In combinatorics on words, a word w over an alphabet\varSigma is said to avoid a pattern p over an alphabet\varDelta of variables if there is no factor f of w such that f= h (p) where …
P Ochem, M Rosenfeld - International Conference on Combinatorics on …, 2017 - Springer
We show that, up to renaming of the letters, the only infinite ternary words avoiding the formula ABCAB. ABCBA. ACB. BAC (resp. ABCA. BCAB. BCB. CBA) have the same set of …
In the interest of studying formulas with reversal of high avoidability index, we find n- avoidance bases for formulas with reversal for n∈{1, 2, 3}. We demonstrate that there is a …
P Ochem - Theoretical Computer Science, 2021 - Elsevier
A family of formulas with reversal of arbitrarily high avoidability index - ScienceDirect Skip to main contentSkip to article Elsevier logo Journals & Books Search RegisterSign in View PDF …
G Badkobeh, P Ochem - RAIRO-Theoretical Informatics and …, 2020 - rairo-ita.org
We construct an infinite word w over the 5-letter alphabet such that for every factor f of w of length at least two, there exists a cyclic permutation of f that is not a factor of w. In other …