freeCodeCamp/curriculum/challenges/english/10-coding-interview-prep/project-euler/problem-441-the-inverse-summation-of-coprime-couples.md
Oliver Eyton-Williams ee1e8abd87
feat(curriculum): restore seed + solution to Chinese (#40683)
* feat(tools): add seed/solution restore script

* chore(curriculum): remove empty sections' markers

* chore(curriculum): add seed + solution to Chinese

* chore: remove old formatter

* fix: update getChallenges

parse translated challenges separately, without reference to the source

* chore(curriculum): add dashedName to English

* chore(curriculum): add dashedName to Chinese

* refactor: remove unused challenge property 'name'

* fix: relax dashedName requirement

* fix: stray tag

Remove stray `pre` tag from challenge file.

Signed-off-by: nhcarrigan <nhcarrigan@gmail.com>

Co-authored-by: nhcarrigan <nhcarrigan@gmail.com>
2021-01-12 19:31:00 -07:00

867 B

id, title, challengeType, forumTopicId, dashedName
id title challengeType forumTopicId dashedName
5900f5261000cf542c510038 Problem 441: The inverse summation of coprime couples 5 302113 problem-441-the-inverse-summation-of-coprime-couples

--description--

For an integer M, we define R(M) as the sum of 1/(p·q) for all the integer pairs p and q which satisfy all of these conditions:

1 ≤ p < q ≤ M p + q ≥ M p and q are coprime.

We also define S(N) as the sum of R(i) for 2 ≤ i ≤ N. We can verify that S(2) = R(2) = 1/2, S(10) ≈ 6.9147 and S(100) ≈ 58.2962.

Find S(107). Give your answer rounded to four decimal places.

--hints--

euler441() should return 5000088.8395.

assert.strictEqual(euler441(), 5000088.8395);

--seed--

--seed-contents--

function euler441() {

  return true;
}

euler441();

--solutions--

// solution required