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freeCodeCamp/curriculum/challenges/english/10-coding-interview-prep/project-euler/problem-343-fractional-sequences.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

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id, title, challengeType, forumTopicId, dashedName
id title challengeType forumTopicId dashedName
5900f4c41000cf542c50ffd6 Problem 343: Fractional Sequences 5 302002 problem-343-fractional-sequences

--description--

For any positive integer k, a finite sequence ai of fractions xi/yi is defined by:

a1 = 1/k and

ai = (xi-1+1)/(yi-1-1) reduced to lowest terms for i>1.

When ai reaches some integer n, the sequence stops. (That is, when yi=1.)

Define f(k) = n.

For example, for k = 20:

1/20 → 2/19 → 3/18 = 1/6 → 2/5 → 3/4 → 4/3 → 5/2 → 6/1 = 6

So f(20) = 6.

Also f(1) = 1, f(2) = 2, f(3) = 1 and Σf(k3) = 118937 for 1 ≤ k ≤ 100.

Find Σf(k3) for 1 ≤ k ≤ 2×106.

--hints--

euler343() should return 269533451410884200.

assert.strictEqual(euler343(), 269533451410884200);

--seed--

--seed-contents--

function euler343() {

  return true;
}

euler343();

--solutions--

// solution required