#include <bits/stdc++.h>
using namespace std;
void solve() {
  int n, m;
  cin >> n;
  cout << (((1ll << (n / 2)) - 1) * 2) << "\n";
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  ;
  int t = 1;
  cin >> t;
  while (t--) solve();
  return 0;
}
