freeCodeCamp/curriculum/challenges/english/08-coding-interview-prep/project-euler/problem-178-step-numbers.english.md

---
id: 5900f41e1000cf542c50ff31
challengeType: 5
title: 'Problem 178: Step Numbers'
forumTopicId: 301813
---

## Description
<section id='description'>
Consider the number 45656.
It can be seen that each pair of consecutive digits of 45656 has a difference of one.
A number for which every pair of consecutive digits has a difference of one is called a step number.
A pandigital number  contains every decimal digit from 0 to 9 at least once.

How many pandigital step numbers less than 1040 are there?
</section>

## Instructions
<section id='instructions'>

</section>

## Tests
<section id='tests'>

```yml
tests:
  - text: <code>euler178()</code> should return 126461847755.
    testString: assert.strictEqual(euler178(), 126461847755);

```

</section>

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

<div id='js-seed'>

```js
function euler178() {
  // Good luck!
  return true;
}

euler178();
```

</div>



</section>

## Solution
<section id='solution'>

```js
// solution required
```

</section>