---
id: 5900f46e1000cf542c50ff81
title: 'Problem 258: A lagged Fibonacci sequence'
challengeType: 5
forumTopicId: 301906
dashedName: problem-258-a-lagged-fibonacci-sequence
---

# --description--

A sequence is defined as:

gk = 1, for 0 ≤ k ≤ 1999 gk = gk-2000 + gk-1999, for k ≥ 2000. Find gk mod 20092010 for k = 1018.

# --hints--

`euler258()` should return 12747994.

```js
assert.strictEqual(euler258(), 12747994);
```

# --seed--

## --seed-contents--

```js
function euler258() {

  return true;
}

euler258();
```

# --solutions--

```js
// solution required
```