public class Reciprcal
{
    public static void main(String[] args)
    {
        double dSum=0;
        long lSun=1;
        for(int i=1;i<21;i++)
        {
            for(int j=1;j<=i;j++)
            {
                lSum*=j;
            }
            System.out.println(lSum);
            dSum+=1/lSum;
        }
        System.out.println("1+1/2.....+1/20!="+dSum);
    }

}

不行啊

不行啊

谢谢了