Suppose you have n integers labelled 1 through n. A permutation of those n integers perm (1-indexed) is considered a beautiful arrangement if for every i (1 <= i <= n), either of the following is true:
perm[i] is divisible by i.i is divisible by perm[i].Given an integer n, return the number of the beautiful arrangements that you can construct.
1 <= n <= 15n = 22n = 11