--- id: 5900f4ed1000cf542c50ffff challengeType: 5 title: 'Problem 383: Divisibility comparison between factorials' videoUrl: '' localeTitle: 问题383:阶乘之间的可比性比较 --- ## Description
设f5(n)是最大整数x,其中5x除以n。例如,f5(625000)= 7。

令T5(n)为满足f5((2·i-1)!)<2·f5(i!)且1≤i≤n的整数i。可以证实T5(103)= 68并且T5(109)= 2408210。

找到T5(1018)。

## Instructions
## Tests
```yml tests: - text: euler383()应该返回22173624649806。 testString: 'assert.strictEqual(euler383(), 22173624649806, "euler383() should return 22173624649806.");' ```
## Challenge Seed
```js function euler383() { // Good luck! return true; } euler383(); ```
## Solution
```js // solution required ```