freeCodeCamp/curriculum/challenges/chinese/10-coding-interview-prep/project-euler/problem-225-tribonacci-non-divisors.md

---
id: 5900f44e1000cf542c50ff60
title: 'Problem 225: Tribonacci non-divisors'
challengeType: 5
forumTopicId: 301868
dashedName: problem-225-tribonacci-non-divisors
---

# --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.

# --hints--

`euler225()` should return 2009.

```js
assert.strictEqual(euler225(), 2009);
```

# --seed--

## --seed-contents--

```js
function euler225() {

  return true;
}

euler225();
```

# --solutions--

```js
// solution required
```