2018-10-10 22:03:03 +00:00
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---
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id: 5900f52c1000cf542c51003f
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2021-02-06 04:42:36 +00:00
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title: 'Problem 448: Average least common multiple'
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2018-10-10 22:03:03 +00:00
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challengeType: 5
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2021-02-06 04:42:36 +00:00
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forumTopicId: 302120
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2021-01-13 02:31:00 +00:00
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dashedName: problem-448-average-least-common-multiple
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2018-10-10 22:03:03 +00:00
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---
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2020-12-16 07:37:30 +00:00
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# --description--
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2018-10-10 22:03:03 +00:00
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2021-02-06 04:42:36 +00:00
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The function lcm(a,b) denotes the least common multiple of a and b.
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2018-10-10 22:03:03 +00:00
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2021-02-06 04:42:36 +00:00
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Let A(n) be the average of the values of lcm(n,i) for 1≤i≤n.
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2018-10-10 22:03:03 +00:00
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2021-02-06 04:42:36 +00:00
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E.g: A(2)=(2+2)/2=2 and A(10)=(10+10+30+20+10+30+70+40+90+10)/10=32.
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Let S(n)=∑A(k) for 1≤k≤n. S(100)=122726.
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Find S(99999999019) mod 999999017.
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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# --hints--
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2018-10-10 22:03:03 +00:00
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2021-02-06 04:42:36 +00:00
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`euler448()` should return 106467648.
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2018-10-10 22:03:03 +00:00
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```js
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2020-12-16 07:37:30 +00:00
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assert.strictEqual(euler448(), 106467648);
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2018-10-10 22:03:03 +00:00
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```
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2021-01-13 02:31:00 +00:00
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# --seed--
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## --seed-contents--
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```js
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function euler448() {
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return true;
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}
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euler448();
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```
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2020-12-16 07:37:30 +00:00
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# --solutions--
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2020-08-13 15:24:35 +00:00
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2021-01-13 02:31:00 +00:00
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```js
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// solution required
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```
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