freeCodeCamp/curriculum/challenges/english/08-coding-interview-prep/project-euler/problem-419-look-and-say-sequence.english.md

---
id: 5900f5101000cf542c510022
challengeType: 5
title: 'Problem 419: Look and say sequence'
---

## Description
<section id='description'>
The look and say sequence goes 1, 11, 21, 1211, 111221, 312211, 13112221, 1113213211, ...
The sequence starts with 1 and all other members are obtained by describing the previous member in terms of consecutive digits.
It helps to do this out loud:
1 is 'one one' → 11
11 is 'two ones' → 21
21 is 'one two and one one' → 1211
1211 is 'one one, one two and two ones' → 111221
111221 is 'three ones, two twos and one one' → 312211
...


Define A(n), B(n) and C(n) as the number of ones, twos and threes in the n'th element of the sequence respectively.
One can verify that A(40) = 31254, B(40) = 20259 and C(40) = 11625.


Find A(n), B(n) and C(n) for n = 1012.
Give your answer modulo 230 and separate your values for A, B and C by a comma.
E.g. for n = 40 the answer would be 31254,20259,11625
</section>

## Instructions
<section id='instructions'>

</section>

## Tests
<section id='tests'>

```yml
tests:
  - text: <code>euler419()</code> should return 998567458, 1046245404, 43363922.
    testString: assert.strictEqual(euler419(), 998567458, 1046245404, 43363922, '<code>euler419()</code> should return 998567458, 1046245404, 43363922.');

```

</section>

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

<div id='js-seed'>

```js
function euler419() {
  // Good luck!
  return true;
}

euler419();
```

</div>



</section>

## Solution
<section id='solution'>

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