Baguenaudier
A Puzzle involving disentangling a set of rings from a looped double rod (also called Chinese Rings). Theminimum number of moves needed for 
rings is
By simultaneously moving the two end rings, the number of moves can be reduced to
The solution of the baguenaudier is intimately related to the theory of Gray Codes.
References
Dubrovsky, V. ``Nesting Puzzles, Part II: Chinese Rings Produce a Chinese Monster.'' Quantum 6, 61-65 (Mar.) and 58-59 (Apr.), 1996. Gardner, M. ``The Binary Gray Code.'' In Knotted Doughnuts and Other Mathematical Entertainments. New York: W. H. Freeman, pp. 15-17, 1986. Kraitchik, M. ``Chinese Rings.'' §3.12.3 in Mathematical Recreations. New York: W. W. Norton, pp. 89-91, 1942. Steinhaus, H. Mathematical Snapshots, 3rd American ed. New York: Oxford University Press, p. 268, 1983.
- Ferrers Diagram
- Ferrers' Function
- Ferrier's Prime
- Feuerbach Circle
- Feuerbach Point
- Feuerbach's Conic Theorem
- Feuerbach's Theorem
- Feynman Point
- FFT
- Fiber
- Fiber Bundle
- Fiber Space
- Fibonacci Dual Theorem
- Fibonacci Hyperbolic Cosine
- Fibonacci Hyperbolic Cotangent
- Fibonacci Hyperbolic Sine
- Fibonacci Hyperbolic Tangent
- Fibonacci Identity
- Fibonacci Matrix
- Fibonacci n-Step Number
- Fibonacci Number
- Fibonacci Polynomial
- Fibonacci Pseudoprime
- Fibonacci Q-Matrix
- Fibonacci Sequence