A Flexagon made by folding a strip into adjacent Equilateral Triangles. The number of states possible in a hexaflexagon is the Catalan Number .
See also Flexagon, Flexatube, Tetraflexagon
References
Cundy, H. and Rollett, A. Mathematical Models, 3rd ed. Stradbroke, England: Tarquin Pub., pp. 205-207, 1989.
Gardner, M. Ch. 1 in The Scientific American Book of Mathematical Puzzles & Diversions. New York:
Simon and Schuster, 1959.
Gardner, M. Ch. 2 in The Second Scientific American Book of Mathematical Puzzles & Diversions: A New Selection.
New York: Simon and Schuster, 1961.
Maunsell, F. G. ``The Flexagon and the Hexaflexagon.'' Math. Gazette 38, 213-214, 1954.
Wheeler, R. F. ``The Flexagon Family.'' Math. Gaz. 42, 1-6, 1958.