Checker-Jumping Problem
Seeks the minimum number of checkers placed on a board required to allow pieces to move by a sequence of horizontalor vertical jumps (removing the piece jumped over) 
rows beyond the forward-most initial checker. The first fewcases are 2, 4, 8, 20. It is, however, impossible to reach level 5.
References
Honsberger, R. Mathematical Gems II. Washington, DC: Math. Assoc. Amer., pp. 23-28, 1976.
- Correlation Integral
- Correlation Ratio
- Correlation (Statistical)
- Cosecant
- Coset
- Cosh
- Cosine
- Cosine Apodization Function
- Cosine Circle
- Cosine Integral
- Cosines Law
- Cosmic Figure
- Cosmological Theorem
- Costa-Hoffman-Meeks Minimal Surface
- Costa Minimal Surface
- Cosymmedian Triangles
- Cotangent
- Cotangent Bundle
- Cotes Circle Property
- Cotes Number
- Cotes' Spiral
- Coth
- Coulomb Wave Function
- Count
- Countable Additivity Probability Axiom