Set Partition
A set partition of a Set 
is a collection of disjoint Subsets of whose Union is . The number of partitions of the Set 
is called a Bell Number.
References
Ruskey, F. ``Info About Set Partitions.'' http://sue.csc.uvic.ca/~cos/inf/setp/SetPartitions.html.
- 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
- Countable Set