freeCodeCamp/curriculum/challenges/chinese/10-coding-interview-prep/project-euler/problem-291-panaitopol-primes.md

---
id: 5900f48f1000cf542c50ffa2
title: 'Problem 291: Panaitopol Primes'
challengeType: 5
forumTopicId: 301943
dashedName: problem-291-panaitopol-primes
---

# --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.

# --hints--

`euler291()` should return 4037526.

```js
assert.strictEqual(euler291(), 4037526);
```

# --seed--

## --seed-contents--

```js
function euler291() {

  return true;
}

euler291();
```

# --solutions--

```js
// solution required
```