---
id: 5900f49d1000cf542c50ffaf
challengeType: 5
title: 'Problem 304: Primonacci'
---
## Description
For any positive integer n the function next_prime(n) returns the smallest prime p such that p>n.
The sequence a(n) is defined by:
a(1)=next_prime(1014) and a(n)=next_prime(a(n-1)) for n>1.
The fibonacci sequence f(n) is defined by:
f(0)=0, f(1)=1 and f(n)=f(n-1)+f(n-2) for n>1.
The sequence b(n) is defined as f(a(n)).
Find ∑b(n) for 1≤n≤100 000.
Give your answer mod 1234567891011.
## Instructions
## Tests
```yml
tests:
- text: euler304() should return 283988410192.
testString: 'assert.strictEqual(euler304(), 283988410192, "euler304() should return 283988410192.");'
```
## Challenge Seed
```js
function euler304() {
// Good luck!
return true;
}
euler304();
```