LetAn be a set such that it contains lists of all combinations of orders numbers from 1 to n.

For instance A2={[1,2],[2,1],[1,1],[2,2]}. These sets have sizes of nn. For setsAn find:

a) A formula for the number of lists in a set, that contain do not contain even numbers when n is even; b)A formula for the number of lists in a set, that contain do not contain even numbers when n is odd; c)A formula for the number of lists in a set, that contain contain only even numbers when n is even;

d)c)A formula for the number of lists in a set, that contain contain only even numbers when n is odd.