java经典问题——求前20项阶乘的和

题目：求1+2!+3!+...+20!的和

public class Practise21 {private void getResult(){int sum = 0;for(int i = 0; i < 20; i ++){sum = sum + getNumber(i);}System.out.println("sum="+sum);}//获得数列的每一项private int getNumber(int i){if(i == 0){return 1;}else{return getNumber(i - 1)*(i + 1);}}public static void main(String[] args) {(new Practise21()).getResult();}}