Find the rules: 9 out of 5, 16 out of 12, 25 out of 21, 36 out of 32_____ ,...,____ (expressed by an algebraic expression containing n)

Find the rules: 9 out of 5, 16 out of 12, 25 out of 21, 36 out of 32_____ ,...,____ (expressed by an algebraic expression containing n)

Find the rule: 9 out of 5, 16 out of 12, 25 out of 21, 36 out of 32, 49 out of 45, and (2 + n) ^ 2 out of n (4 + n)