Infinite ternary square-free words concatenated from permutations of a single word
We answer a question of Harju: An infinite square-free ternary word with an n-stem factorization exists for any n >= 13. We show that there are square-free uniform ternary morphisms of length k for every k >= 23. This resolves almost completely a problem of the author and Rampersad. (C) 2013 Elsevier B.V. All rights reserved.
square-free words morphisms combinatorics on words