#include<iostream>
using namespace std;
const int maxn=32;
int arr[maxn]={0,1,3};
void func( void )
{
for(int i=3;i<=maxn;i++ )
arr[i]=arr[i-1]+2*arr[i-2];
}
int main( void )
int t,n;
func();
cin>>t;
while(t--)
cin>>n;
cout<<arr[n]<<endl;
return 0;