C(n, k) = .
A function that is defined only for a set of numbers that can be listed, such as the set of whole numbers or the set of integers.
A definition of a function by a formula in terms of the variable.
F(n) = n(n - 1)(n - 2)(n - 3) ... (2)(1)
where n is a non-negative integer.
We define F(0) = 1 and F(1) = 1.
The sequence 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, ..., where each value is the sum of the preceding two values. Defined recursively by:
P(n, k) =
A definition of a function in terms of the same function of a smaller variable.