C :

#include<stdio.h>

int main()
{
	int c,n,i,a[20];
	a[0]=3;
	a[1]=7;
	for(i=2;i<20;i++)
		a[i]=a[i-1]*2+a[i-2];
	scanf("%d",&c);
	while(c--)
	{
		scanf("%d",&n);
		printf("%d\n",a[n-1]);
	}
	return 0;
}

C++ :

#include<stdio.h>

int main()
{
	int c,n,i,a[20];
	a[0]=3;
	a[1]=7;
	for(i=2;i<20;i++)
		a[i]=a[i-1]*2+a[i-2];
	scanf("%d",&c);
	while(c--)
	{
		scanf("%d",&n);
		printf("%d\n",a[n-1]);
	}
	return 0;
}

Pascal :

program p1060;
var a:array[0..20] of longint;
    c,i,j,k,n:longint;
begin
  readln(c);
  a[0]:=1;
  a[1]:=3;
  for i:=2 to 20 do
   a[i]:=2*a[i-1]+a[i-2];
  for j:=1 to c do
   begin
     readln(n);
     writeln(a[n]);
   end;
end.

Java :

import java.util.Scanner;
public class Main{
    public static void main(String arg[]) {
        Scanner cin=new Scanner(System.in) ;   
        int a[]=new int[20];
        a[0]=3;
        a[1]=7;
        for(int i=2;i<20;i++)
             a[i]=a[i-1]*2+a[i-2];
        int c,j;
        c=cin.nextInt();
        while (cin.hasNext())
        {for(int i=0;i<c;i++)
           {j=cin.nextInt();
               System.out.println(a[j-1]);  
           }
        }}}

Python :

# coding=utf-8
a=int(input())
for i in range(a):
    b=int(input())
    n=1
    m=1
    L=0
    R=0
    for j in range(b):
        L=n+m
        R=n*2+m
        n=L
        m=R
    print(R)