Above the Main Diagonal

import java.util.Arrays;
import java.util.Scanner;

public class Task {

    public static void main(String[] args) {

        Scanner scanner = new Scanner(System.in);
        int number = Integer.parseInt(scanner.nextLine());
        int rows = number;
        int cols = number;
        long sum = 0;
        int power = 0;
        int counter = 1;
        long[][] matrix = new long[number][number];

        for (int i = 0; i < rows; i++) {
            for (int j = 0; j < cols; j++) {
                matrix[i][j] = (long)Math.pow(2, power);
                power++;
//                System.out.print(matrix[i][j]);
            }
//            System.out.println();
            power = counter;
            counter++;
        }
        //calc the sum
        for (int i = 1; i < cols; i++) {
            for (int j = i - 1; j >= 0; j--) {
                sum += matrix[i][j];
            }
        }
        System.out.println(sum);
    }
}