B'Phoenix has n coins with weights 2^1, 2^2, ... , 2^n . He knows that n is even. He wants to split the coins into two piles such that each pile has exactly frac{n}{2} coins and the difference of weights between the two piles is minimized. Formally, let a denote the sum of weights in the first pile, and b denote the sum of weights in the second pile. Help Phoenix minimize |a-b| , the absolute value of a-b . The input consists of multiple test cases. The first line contains an integer t ( 1 <= t <= 100 ) -- the number of test cases. The first line of each test case contains an integer n ( 2 <= n <= 30 ; n is even) -- the number of coins that Phoenix has. For each test case, output one integer -- the minimum possible difference of weights between the two piles. In the first test case, Phoenix has two coins with weights 2 and 4 . No matter how he divides the coins, the difference will be 4-2=2 . In the second test case, Phoenix has four coins of weight 2 , 4 , 8 , and 16 . It is optimal for Phoenix to place coins with weights 2 and 16 in one pile, and coins with weights 4 and 8 in another pile. The difference is (2+16)-(4+8)=6 . '...