--- id: 5900f46b1000cf542c50ff7d challengeType: 5 title: 'Problem 254: Sums of Digit Factorials' --- ## Description
Define f(n) as the sum of the factorials of the digits of n. For example, f(342) = 3! + 4! + 2! = 32. Define sf(n) as the sum of the digits of f(n). So sf(342) = 3 + 2 = 5. Define g(i) to be the smallest positive integer n such that sf(n) = i. Though sf(342) is 5, sf(25) is also 5, and it can be verified that g(5) is 25. Define sg(i) as the sum of the digits of g(i). So sg(5) = 2 + 5 = 7. Further, it can be verified that g(20) is 267 and ∑ sg(i) for 1 ≤ i ≤ 20 is 156. What is ∑ sg(i) for 1 ≤ i ≤ 150?
## Instructions
## Tests
```yml tests: - text: euler254() should return 8184523820510. testString: 'assert.strictEqual(euler254(), 8184523820510, "euler254() should return 8184523820510.");' ```
## Challenge Seed
```js function euler254() { // Good luck! return true; } euler254(); ```
## Solution
```js // solution required ```