47 lines
742 B
Markdown
47 lines
742 B
Markdown
|
---
|
||
|
id: 5900f52c1000cf542c51003f
|
||
|
title: 'Problem 448: Average least common multiple'
|
||
|
challengeType: 5
|
||
|
forumTopicId: 302120
|
||
|
dashedName: problem-448-average-least-common-multiple
|
||
|
---
|
||
|
|
||
|
# --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.
|
||
|
|
||
|
# --hints--
|
||
|
|
||
|
`euler448()` should return 106467648.
|
||
|
|
||
|
```js
|
||
|
assert.strictEqual(euler448(), 106467648);
|
||
|
```
|
||
|
|
||
|
# --seed--
|
||
|
|
||
|
## --seed-contents--
|
||
|
|
||
|
```js
|
||
|
function euler448() {
|
||
|
|
||
|
return true;
|
||
|
}
|
||
|
|
||
|
euler448();
|
||
|
```
|
||
|
|
||
|
# --solutions--
|
||
|
|
||
|
```js
|
||
|
// solution required
|
||
|
```
|