Morphisms, Squarefree Strings, and the Tower of Hanoi Puzzle
Jean‐Paul Allouche, Dan Astoorian, Jim Randall, Jeffrey O. Shallit · American Mathematical Monthly · 1994
Jean-Paul Allouche, Dan Astoorian, Jim Randall, Jeffrey Shallit, Morphisms, Squarefree Strings, and the Tower of Hanoi Puzzle, The American Mathematical Monthly, Vol. 101, No. 7 (Aug. - Sep., 1994), pp. 651-658