Permutations(k,n)

The number of possible permutations of k items taken from a bucket of n items.

Library

Advanced math

Permutations(2,4) → 12

They are: {1,2}, {1,3}, {1,4},{2,1}, {2,3}, {2,4}, {3,1}, {3,2}, {3,4}, {4,1}, {4,2}, {4,3}