Rubik's Clock

A puzzle consisting of 18 small clocks. There are $12^{18}$ possible configurations, although not all are realizable.

See also Rubik's Cube

References

Dénes, J. and Mullen, G. L. ``Rubik's Clock and Its Solution.'' Math. Mag. 68, 378-381, 1995.

Zeilberger, D. ``Doron Zeilberger's Maple Packages and Programs: RubikClock.'' http://www.math.temple.edu/~zeilberg/programs.html.