freeCodeCamp/curriculum/challenges/english/08-coding-interview-prep/project-euler/problem-291-panaitopol-primes.english.md

---
id: 5900f48f1000cf542c50ffa2
challengeType: 5
title: 'Problem 291: Panaitopol Primes'
---

## Description
<section id='description'>
A prime number p is called a Panaitopol prime if  for some positive integersx and y.


Find how many Panaitopol primes are less than 5×1015.
</section>

## Instructions
<section id='instructions'>

</section>

## Tests
<section id='tests'>

```yml
tests:
  - text: <code>euler291()</code> should return 4037526.
    testString: assert.strictEqual(euler291(), 4037526, '<code>euler291()</code> should return 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>