Suppose you have n integers labeled 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. Example 1: Input: n = 2 Output: 2 Explanation: The first beautiful arrangement is [1,2]: - perm[1] = 1 is divisible by i = 1 - perm[2] = 2 is divisible by i = 2 The second beautiful arrangement is [2,1]: - perm[1] = 2 is divisible by i = 1 - i = 2 is divisible by perm[2] = 1 Example 2: Input: n = 1 Output: 1 Constraints: 1 <= n <= 15