hdoj 2501

#include<iostream>
using namespace std;

int main()
{
        int T,N;
        long long f[30] = {0};
        f[1] = 1;
        f[2] = 3;
        for(int i=3;i<=30;i++)
        {
                f[i] = f[i-1] + f[i-2]*2;
        }
        cin>>T;
        for(int i=0;i<T;i++)
        {
                cin>>N;
                cout<<f[N]<<endl;
        }
        return 0;
}