UVA - 11310 - Delivery Debacle

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {

    public static void main(String[] args) throws IOException {
         BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringBuffer sb = new StringBuffer("");
        long arr[]=new long[41];
        arr[1]=1;
        arr[2]=5;
        arr[3]=11;
        for(int i=4;i<41;i++){
            arr[i]= arr[i-1] + 4*arr[i-2] + 2*arr[i-3];
        }
        int cases=Integer.parseInt(br.readLine());
        for(int i=0;i<cases;i++) {
            int x = Integer.parseInt(br.readLine());
            sb.append(arr[x]).append("\n");
        }
        System.out.print(sb);
    }
}