freeCodeCamp/curriculum/challenges/english/08-coding-interview-prep/project-euler/problem-225-tribonacci-non-divisors.english.md

---
id: 5900f44e1000cf542c50ff60
challengeType: 5
title: 'Problem 225: Tribonacci non-divisors'
---

## Description
<section id='description'>
The sequence 1, 1, 1, 3, 5, 9, 17, 31, 57, 105, 193, 355, 653, 1201 ...
is defined by T1 = T2 = T3 = 1 and Tn = Tn-1 + Tn-2 + Tn-3.


It can be shown that 27 does not divide any terms of this sequence.In fact, 27 is the first odd number with this property.

Find the 124th odd number that does not divide any terms of the above sequence.
</section>

## Instructions
<section id='instructions'>

</section>

## Tests
<section id='tests'>

```yml
tests:
  - text: <code>euler225()</code> should return 2009.
    testString: assert.strictEqual(euler225(), 2009, '<code>euler225()</code> should return 2009.');

```

</section>

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

<div id='js-seed'>

```js
function euler225() {
  // Good luck!
  return true;
}

euler225();
```

</div>



</section>

## Solution
<section id='solution'>

```js
// solution required
```
</section>