freeCodeCamp/curriculum/challenges/english/10-coding-interview-prep/project-euler/problem-254-sums-of-digit-factorials.md

id, title, challengeType, forumTopicId, dashedName

id	title	challengeType	forumTopicId	dashedName
5900f46b1000cf542c50ff7d	Problem 254: Sums of Digit Factorials	5	301902	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 \sum sg(i) for 1 ≤ i ≤ 20 is 156.

What is \sum sg(i) for 1 ≤ i ≤ 150?

--hints--

sumsOfDigitFactorials() should return 8184523820510.

assert.strictEqual(sumsOfDigitFactorials(), 8184523820510);

--seed--

--seed-contents--

function sumsOfDigitFactorials() {

  return true;
}

sumsOfDigitFactorials();

--solutions--

// solution required