Let $n$ be a positive integer. Consider an $n \times n$ matrix with entries $1,2, \ldots, n^{2}$ written in order starting top left and moving along each row in turn left-to-right. We choose $n$ entries of the matrix such that exactly one entry is chosen in each row and each column. What are the possible values of the sum of the selected entries? Please provide the value when n = 2. 

Let's think step by step and output the final answer within \boxed{}.
user