There are ternary circular square-free words of length $n$ for $n\ge$ 18.

Currie, James D.. "There are ternary circular square-free words of length for 18.." The Electronic Journal of Combinatorics [electronic only] 9.1 (2002): Research paper N10, 7 p.-Research paper N10, 7 p.. <http://eudml.org/doc/124300>.

@article{Currie2002,
author = {Currie, James D.},
journal = {The Electronic Journal of Combinatorics [electronic only]},
keywords = {combinatorics on words; square-free words},
language = {eng},
number = {1},
pages = {Research paper N10, 7 p.-Research paper N10, 7 p.},
publisher = {Prof. André Kündgen, Deptartment of Mathematics, California State University San Marcos, San Marcos},
title = {There are ternary circular square-free words of length for 18.},
url = {http://eudml.org/doc/124300},
volume = {9},
year = {2002},
}

TY - JOUR
AU - Currie, James D.
TI - There are ternary circular square-free words of length for 18.
JO - The Electronic Journal of Combinatorics [electronic only]
PY - 2002
PB - Prof. André Kündgen, Deptartment of Mathematics, California State University San Marcos, San Marcos
VL - 9
IS - 1
SP - Research paper N10, 7 p.
EP - Research paper N10, 7 p.
LA - eng
KW - combinatorics on words; square-free words
UR - http://eudml.org/doc/124300
ER -