백준 3단계 no.3

import java.util.*;

public class Main{
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        
        int n = sc.nextInt();
        
        int sum=0;
        
        for(int i = 1; i <= n; i++) {
            sum += i;
        }
        
        System.out.print(sum);
    }
}

<오답>

import java.util.*;

public class Main{
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        
        int n = sc.nextInt();
        
        int i;
        
        for(i = 0; i <= n; i++) {
            i += i;
        }
        
        System.out.print(i);
    }
}