---
id: 5900f48f1000cf542c50ffa2
challengeType: 5
videoUrl: ''
title: 问题291：Panaitopol素数
---

## Description
<section id="description">
如果对于某些正整数x和y，素数p称为Panaitopol素数。


找出多少个Panaitopol素数小于5×1015。
</section>

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

## Tests
<section id='tests'>

```yml
tests:
  - text: <code>euler291()</code>应该返回4037526。
    testString: assert.strictEqual(euler291(), 4037526);

```

</section>

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

<div id='js-seed'>

```js
function euler291() {
  // Good luck!
  return true;
}

euler291();

```

</div>



</section>

## Solution
<section id='solution'>

```js
// solution required
```

/section>