6 papers
Half-flips are 5-avoidable
Pascal Ochem
A word contains a \emph{half-flip} if it contains non-empty factors and where . Fici reports a non-constructive proof of the existence of an infinite word over a…
Pairs of square-free arithmetic progressions in infinite words
Thomas Delépine, Pascal Ochem, Matthieu Rosenfeld
We study a question of Harju from 2019 regarding the existence of infinite ternary square-free words whose subsequences modulo and are also square-free for relatively prime…
Critical exponent of ternary words with few distinct palindromes
Ľubomíra Dvořáková, Lucas Mol, Pascal Ochem
We study infinite ternary words that contain few distinct palindromes. In particular, we classify such words according to their critical exponent.
4-tangrams are 4-avoidable
Pascal Ochem, Théo Pierron
A tangram is a word in which every letter occurs an even number of times. Thus it can be cut into parts that can be arranged into two identical words. The \emph{cut number} of a ta…
More characterizations of morphic words
Golnaz Badkobeh, Pascal Ochem
An interesting phenomenon in combinatorics on words is when every recurrent word satisfying some avoidance constraints has the same factor set as a morphic word. An early example i…
Critical exponent of binary words with few distinct palindromes
L'ubomíra Dvořáková, Pascal Ochem, Daniela Opočenská
We study infinite binary words that contain few distinct palindromes. In particular, we classify such words according to their critical exponents. This extends results by Fici and…