nPk ( n k -- nPk )


Vocabulary
math.combinatorics

Inputs and outputs
na non-negative integer
ka non-negative integer
nPkan integer


Word description
Outputs the total number of unique permutations of size k (order does matter) that can be taken from a set of size n.

Examples
USING: math.combinatorics prettyprint ; 10 4 nPk .
5040


Definition