2020/07/07 by Marko Milosevic, Narad Rampersad, Milosevic, Marko +1
Computer Science · Mathematics · #68R15 #Combinatorics (math.CO) #FOS: Computer and information sciences #FOS: Mathematics #Formal Languages and Automata Theory (cs.FL) #cs.FL #math.CO #msc:68R15
paper · pdf · doi:10.48550/arxiv.2007.03557
10 pages
arxiv created 2020/07/07 · arxiv updated 2020/07/08
We give a partial answer to a problem of Harju by constructing an infinite ternary squarefree word w with the property that for every k ≥ 3312 there is an interior length-k factor of w that can be deleted while still preserving squarefreeness. We also examine Thue's famous squarefree word (generated by iterating the map 0 → 012, 1 → 02, 2 → 1) and characterize the positions i for which deleting the symbol appearing at position i preserves squarefreeness.