Plz tell me the reason of my program outputs?

Class Number {

public static void main(String arg[])
{
int i,j,n=4;


for(i=1;i<5;i++)
{
for(j=n;j<(n+1);j=j*j)
{
System.out.println(j);
}
n=j;
}

}

}

my program is working when n=2,n=3,n=7; but not working for n=4; n=5; n=9.....why....? plz help me