Permutations of the integers 1 to N, yes. You can look at each permutation as a (unique, one-to-one and onto) function from the set [1,2,3,...N] to positions l

Permutations of the integers 1 to N, yes. You can look at each permutation as a (unique, one-to-one and onto) function from the set [1,2,3,...N] to positions labeled also [1,2,3,...N]. For it to be a permutation, each position needs to contain a single value, and each value needs to be at one single location. Since the domain and range of the function have the same (finite) number of elements, either of these properties implies the other.