New results on pseudosquare avoidance
Formal Languages and Automata Theory
2019-04-22 v1 Discrete Mathematics
Combinatorics
Abstract
We start by considering binary words containing the minimum possible numbers of squares and antisquares (where an antisquare is a word of the form ), and we completely classify which possibilities can occur. We consider avoiding , where is any permutation of the underlying alphabet, and , where is any transformation of the underlying alphabet. Finally, we prove the existence of an infinite binary word simultaneously avoiding all occurrences of for every nonerasing morphism and all sufficiently large words .
Keywords
Cite
@article{arxiv.1904.09157,
title = {New results on pseudosquare avoidance},
author = {Tim Ng and Pascal Ochem and Narad Rampersad and Jeffrey Shallit},
journal= {arXiv preprint arXiv:1904.09157},
year = {2019}
}