freeCodeCamp/curriculum/challenges/english/08-coding-interview-prep/project-euler/problem-233-lattice-points-on-a-circle.english.md

---
id: 5900f4551000cf542c50ff68
challengeType: 5
title: 'Problem 233: Lattice points on a circle'
---

## Description
<section id='description'>
Let f(N) be the number of points with integer coordinates that are on a circle passing through (0,0), (N,0),(0,N), and (N,N).
It can be shown that f(10000) = 36.

What is the sum of all positive integers N ≤ 1011 such that f(N) = 420 ?
</section>

## Instructions
<section id='instructions'>

</section>

## Tests
<section id='tests'>

```yml
tests:
  - text: <code>euler233()</code> should return 271204031455541300.
    testString: assert.strictEqual(euler233(), 271204031455541300, '<code>euler233()</code> should return 271204031455541300.');

```

</section>

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

<div id='js-seed'>

```js
function euler233() {
  // Good luck!
  return true;
}

euler233();
```

</div>



</section>

## Solution
<section id='solution'>

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