freeCodeCamp/curriculum/challenges/english/08-coding-interview-prep/project-euler/problem-162-hexadecimal-numbers.english.md

---
id: 5900f40e1000cf542c50ff21
challengeType: 5
title: 'Problem 162: Hexadecimal numbers'
forumTopicId: 301796
---

## Description
<section id='description'>
In  the hexadecimal number system numbers are represented using 16 different digits:
0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F
The hexadecimal number AF when written in the decimal number system equals 10x16+15=175.
In the 3-digit hexadecimal numbers 10A, 1A0, A10, and A01 the digits 0,1 and A are all present.
Like numbers written in base ten we write hexadecimal numbers without leading zeroes.
How many hexadecimal numbers containing at most sixteen hexadecimal digits exist with all of the digits 0,1, and A present at least once?
Give your answer as a hexadecimal number.
(A,B,C,D,E and F in upper case, without any leading or trailing code that marks the number as hexadecimal and without leading zeroes , e.g. 1A3F and not: 1a3f and not 0x1a3f and not $1A3F and not #1A3F and not 0000001A3F)
</section>

## Instructions
<section id='instructions'>

</section>

## Tests
<section id='tests'>

```yml
tests:
  - text: <code>euler162()</code> should return 3D58725572C62302.
    testString: assert.strictEqual(euler162(), '3D58725572C62302');

```

</section>

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

<div id='js-seed'>

```js
function euler162() {
  // Good luck!
  return true;
}

euler162();
```

</div>



</section>

## Solution
<section id='solution'>

```js
// solution required
```

</section>