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---
id: 5900f3c51000cf542c50fed6
challengeType: 5
title: 'Problem 88: Product-sum numbers'
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forumTopicId: 302203
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---
## Description
< section id = 'description' >
A natural number, N, that can be written as the sum and product of a given set of at least two natural numbers, {a1, a2, ... , ak} is called a product-sum number: N = a1 + a2 + ... + ak = a1 × a2 × ... × ak.
For example, 6 = 1 + 2 + 3 = 1 × 2 × 3.
For a given set of size, k, we shall call the smallest N with this property a minimal product-sum number. The minimal product-sum numbers for sets of size, k = 2, 3, 4, 5, and 6 are as follows.
k=2: 4 = 2 × 2 = 2 + 2k=3: 6 = 1 × 2 × 3 = 1 + 2 + 3k=4: 8 = 1 × 1 × 2 × 4 = 1 + 1 + 2 + 4k=5: 8 = 1 × 1 × 2 × 2 × 2 = 1 + 1 + 2 + 2 + 2k=6: 12 = 1 × 1 × 1 × 1 × 2 × 6 = 1 + 1 + 1 + 1 + 2 + 6
Hence for 2≤k≤6, the sum of all the minimal product-sum numbers is 4+6+8+12 = 30; note that 8 is only counted once in the sum.
In fact, as the complete set of minimal product-sum numbers for 2≤k≤12 is {4, 6, 8, 12, 15, 16}, the sum is 61.
What is the sum of all the minimal product-sum numbers for 2≤k≤12000?
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## Instructions
< section id = 'instructions' >
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## Tests
< section id = 'tests' >
```yml
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tests:
- text: < code > euler88()</ code > should return 7587457.
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testString: assert.strictEqual(euler88(), 7587457);
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```
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## Challenge Seed
< section id = 'challengeSeed' >
< div id = 'js-seed' >
```js
function euler88() {
// Good luck!
return true;
}
euler88();
```
< / div >
< / section >
## Solution
< section id = 'solution' >
```js
// solution required
```
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< / section >