Java编写程序实现求1!+2!+3+...+20!。

public class Factorial {
    public static void main(String[] args) {
        long result = 1;
        for (int i = 1; i <= 20; i++) {
            result *= i;
            System.out.println(i + "! = " + result);
        }
    }
}

输出结果为：

1! = 1
2! = 2
3! = 6
4! = 24
5! = 120
6! = 720
7! = 5040
8! = 40320
9! = 362880
10! = 3628800
11! = 39916800
12! = 479001600
13! = 6227020800
14! = 87178291200
15! = 1307674368000
16! = 20922789888000
17! = 355687428096000
18! = 6402373705728000
19! = 121645100408832000
20! = 2432902008176640000