---
id: 5900f4741000cf542c50ff86
challengeType: 5
title: 'Problem 263: An engineers'' dream come true'
---

## Description
<section id='description'>
Consider the number 6. The divisors of 6 are: 1,2,3 and 6.
Every number from 1 up to and including 6 can be written as a sum of distinct divisors of 6:
1=1, 2=2, 3=1+2, 4=1+3, 5=2+3, 6=6.
A number n is called a practical number if every number from 1 up to and including n can be expressed as a sum of distinct divisors of n.


A pair of consecutive prime numbers with a difference of six is called a sexy pair (since "sex" is the Latin word for "six"). The first sexy pair is (23, 29).


We may occasionally find a triple-pair, which means three consecutive sexy prime pairs, such that the second member of each pair is the first member of the next pair.


We shall call a number n such that :
(n-9, n-3), (n-3,n+3), (n+3, n+9) form a triple-pair, and
the numbers n-8, n-4, n, n+4 and n+8 are all practical,

an engineers’ paradise.


Find the sum of the first four engineers’ paradises.
</section>

## Instructions
<section id='instructions'>

</section>

## Tests
<section id='tests'>

```yml
tests:
  - text: <code>euler263()</code> should return 2039506520.
    testString: assert.strictEqual(euler263(), 2039506520, '<code>euler263()</code> should return 2039506520.');

```

</section>

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

<div id='js-seed'>

```js
function euler263() {
  // Good luck!
  return true;
}

euler263();
```

</div>



</section>

## Solution
<section id='solution'>

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