freeCodeCamp/curriculum/challenges/english/10-coding-interview-prep/project-euler/problem-448-average-least-common-multiple.english.md
mrugesh 22afc2a0ca feat(learn): python certification projects (#38216)
Co-authored-by: Oliver Eyton-Williams <ojeytonwilliams@gmail.com>
Co-authored-by: Kristofer Koishigawa <scissorsneedfoodtoo@gmail.com>
Co-authored-by: Beau Carnes <beaucarnes@gmail.com>
2020-05-27 13:19:08 +05:30

972 B

id, challengeType, isHidden, title, forumTopicId
id challengeType isHidden title forumTopicId
5900f52c1000cf542c51003f 5 false Problem 448: Average least common multiple 302120

Description

The function lcm(a,b) denotes the least common multiple of a and b. Let A(n) be the average of the values of lcm(n,i) for 1≤i≤n. E.g: A(2)=(2+2)/2=2 and A(10)=(10+10+30+20+10+30+70+40+90+10)/10=32.

Let S(n)=∑A(k) for 1≤k≤n. S(100)=122726.

Find S(99999999019) mod 999999017.

Instructions

Tests

tests:
  - text: <code>euler448()</code> should return 106467648.
    testString: assert.strictEqual(euler448(), 106467648);

Challenge Seed

function euler448() {
  // Good luck!
  return true;
}

euler448();

Solution

// solution required