java - Project Euler 5，我得到的答案只有一半，为什么？

Question

我正在研究欧拉项目 5:

2520 is the smallest number that can be divided by each of the numbers from 1 to 10 without any remainder.

What is the smallest positive number that is evenly divisible by all of the numbers from 1 to 20?

但是，我不断得到的答案 116396280 只是实际答案的一半。我哪里错了？为什么我只得到一半的答案？顺便说一下，这是用java编写的。

public class main{
    public static void main(String[] args){
        long number=2520;//smallest number divisible by all numbers from 1-10
        long x;//for loop counter
        for (x=19;x>10;x-=2){
            if (x!=15){//its factors 5 and 3 have already been counted
                number*=x;//multiplies new prime numbers
            }
        }
       System.out.println(number);
    }
}

Answer 1

如果只遍历奇数，您会错过 16，其因式分解为 2⁴ 您的答案仅包含 2³。