freeCodeCamp/curriculum/challenges/english/08-coding-interview-prep/project-euler/problem-393-migrating-ants.english.md

---
id: 5900f4f61000cf542c510008
challengeType: 5
title: 'Problem 393: Migrating ants'
forumTopicId: 302058
---

## Description
<section id='description'>
An  n×n grid of squares contains  n2 ants, one ant per square.
All ants decide to move simultaneously to an adjacent square (usually 4 possibilities, except for ants on the edge of the grid or at the corners).
We define f(n) to be the number of ways this can happen without any ants ending on the same square and without any two ants crossing the same edge between two squares.


You are given that f(4) = 88.
Find  f(10).
</section>

## Instructions
<section id='instructions'>

</section>

## Tests
<section id='tests'>

```yml
tests:
  - text: <code>euler393()</code> should return 112398351350823100.
    testString: assert.strictEqual(euler393(), 112398351350823100);

```

</section>

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

<div id='js-seed'>

```js
function euler393() {
  // Good luck!
  return true;
}

euler393();
```

</div>



</section>

## Solution
<section id='solution'>

```js
// solution required
```

</section>