Disposability in square-free words
: Tero Harju
Publisher: Elsevier B.V.
: 2021
: Theoretical Computer Science
: Theoretical Computer Science
: 0304-3975
DOI: https://doi.org/10.1016/j.tcs.2020.07.030
We consider words w over the alphabet Σ={ 0, 1, 2 }. It is shown that there are irreducibly square-free words of all lengths n except 4,5,7 and 12. Such a word is square-free (i.e., it has no repetitions uu as factors), but by removing any one internal letter creates a square in the word.