Direct definition of a ternary infinite square-free sequence
arXiv:0712.0139 · doi:10.1016/j.ipl.2007.11.012
Abstract
We propose a new ternary infinite (even full-infinite) square-free sequence. The sequence is defined both by an iterative method and by a direct definition. Both definitions are analogous to those of the Thue-Morse sequence. The direct definition is given by a deterministic finite automaton with output. In short, the sequence is automatic.
9 pages, 1 figures, to appear in Information Processing Letters