---
id: 5900f3721000cf542c50fe85
challengeType: 5
title: 'Problem 6: Sum square difference'
videoUrl: ''
localeTitle: 问题6：求和方差
---

## Description
<section id="description">前十个自然数的平方和是， <div style="text-align: center;"> 1 <sup>2</sup> + 2 <sup>2</sup> + ... + 10 <sup>2</sup> = 385 </div>前十个自然数之和的平方是， <div style="text-align: center;"> （1 + 2 + ... + 10） <sup>2</sup> = 55 <sup>2</sup> = 3025 </div>因此，前十个自然数的平方和与和的平方之间的差值为3025  -  385 = 2640.求出前<code>n</code>自然数的平方和与总和的平方之间的差值。 </section>

## Instructions
<section id="instructions">
</section>

## Tests
<section id='tests'>

```yml
tests:
  - text: <code>sumSquareDifference(10)</code>应该返回2640。
    testString: 'assert.strictEqual(sumSquareDifference(10), 2640, "<code>sumSquareDifference(10)</code> should return 2640.");'
  - text: <code>sumSquareDifference(20)</code>应该返回41230。
    testString: 'assert.strictEqual(sumSquareDifference(20), 41230, "<code>sumSquareDifference(20)</code> should return 41230.");'
  - text: <code>sumSquareDifference(100)</code>应该返回25164150。
    testString: 'assert.strictEqual(sumSquareDifference(100), 25164150, "<code>sumSquareDifference(100)</code> should return 25164150.");'

```

</section>

## Challenge Seed
<section id='challengeSeed'>

<div id='js-seed'>

```js
function sumSquareDifference(n) {
  // Good luck!
  return true;
}

sumSquareDifference(100);

```

</div>



</section>

## Solution
<section id='solution'>

```js
// solution required
```
</section>
