- permutations n kprocedure
- n
- integer
- k
- integer
Returns the number of ways to choose a sequence of k items from a set of n items; i.e. the order of the k items is significant. Both arguments must be nonnegative.
When k > n, (permutations n k) = 0. Otherwise, (permutations n k) is equivalent to (/ (factorial n) (factorial (- n k))).
> (permutations 5 3) 60
Wikipedia: Permutations