#include <bits/stdc++.h>   using namespace std;   int main() {     int t;     cin >> t;     for (int i = 0; i < t; i++) {       int n;       cin >> n;       int a[n];       for (int j = 1; j <= n; j++) {         a[j] = pow(2, j);       }       int f = 0, s = 0;       for (int j = 1; j <= n; j++) {         if (j < n / 2 || j == n)           f += a[j];         else {           s += a[j];         }       }       cout << f - s << endl;     }     return 0;   }   