C Programming to find sum of first n even natural numbers

/*to find the sum of first n even natural number*/
#include<stdio.h>
#include<stdlib.h>
int main( )
{
    int i,j=2,n,sum=0;
    printf ("enter n: ");
    scanf ("%d",&n);
    for (i=1; i<=n; i++)
    {
        sum+=j;
        j+=2;
    }
    printf ("\nsum of even natural number=%d",sum);
    system ("pause");
    return 0;
}