阶乘数列1064

解题思路:

注意事项:

参考代码:

public class Main {

    public static void main(String args[]) {

        double sum = 0;

        double a = 1;

        for (int i = 1; i <= 30; i++) {

            a = 1;

            for (int x = 1; x <= i; x++) {

                a*=x;

            }

            sum+=a;

        }

        System.out.printf("%.2e", sum);

    }

}