45 lines
731 B
Markdown
45 lines
731 B
Markdown
---
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id: 5900f5231000cf542c510035
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title: 'Problem 439: Sum of sum of divisors'
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challengeType: 5
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forumTopicId: 302110
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dashedName: problem-439-sum-of-sum-of-divisors
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---
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# --description--
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Let d(k) be the sum of all divisors of k.
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We define the function S(N) = ∑1≤i≤N ∑1≤j≤Nd(i·j).
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For example, S(3) = d(1) + d(2) + d(3) + d(2) + d(4) + d(6) + d(3) + d(6) + d(9) = 59.
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You are given that S(103) = 563576517282 and S(105) mod 109 = 215766508. Find S(1011) mod 109.
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# --hints--
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`euler439()` should return 968697378.
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```js
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assert.strictEqual(euler439(), 968697378);
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```
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# --seed--
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## --seed-contents--
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```js
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function euler439() {
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return true;
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}
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euler439();
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```
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# --solutions--
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```js
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// solution required
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```
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