// Write a program to sum first n even numbers using for loop

public class CWH_PS5 {
    public static void main(String[] args) {
      int sum =0;
      int n = 5;
      for(int i = 0 ; i < n; i++){
          sum = sum + (2*i);
      }
        System.out.print("sum of first n numbers: ");
        System.out.println(sum);
    }
}

//output 
sum of first n numbers: 20

Process finished with exit code 0