A. Phoenix and Balancetime limit per test2 secondsmemory limit per test256 megabytesinputstandard inputoutputstandard outputPhoenix has n coins with weights 2^1, 2^2, \dots, 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.InputThe input consists of multiple test cases. The first line contains an integer t (1 \le t \le 100) — the number of test cases.The first line of each test case contains an integer n (2 \le n \le 30; n is even) — the number of coins that Phoenix has. OutputFor each test case, output one integer — the minimum possible difference of weights between the two piles.ExampleInput
2
2
4
Output
2
6
NoteIn 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.
2
2
4

2 6 
['greedy', 'math', '*800']