1 #include<iostream>
 2 #include<cstdio>
 3 #include<cstring>
 4 using namespace std;
 5 int main()
 6 {
 7     int t,n;
 8     int a[22];
 9     a[0]=1;a[1]=3;
10     for(int i=2;i<=20;i++)
11     a[i]=a[i-1]*2+a[i-2];
12     scanf("%d",&t);
13     while(t--)
14     {
15         scanf("%d",&n);
16         printf("%d\n",a[n]);
17     }
18     return 0;
19 }