43 lines
667 B
Markdown
43 lines
667 B
Markdown
---
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id: 5900f51e1000cf542c510030
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title: 'Problem 432: Totient sum'
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challengeType: 5
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forumTopicId: 302103
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dashedName: problem-432-totient-sum
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---
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# --description--
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Let $S(n, m) = \sum φ(n × i)$ for $1 ≤ i ≤ m$. ($φ$ is Euler's totient function)
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You are given that $S(510\\,510, {10}^6) = 45\\,480\\,596\\,821\\,125\\,120$.
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Find $S(510\\,510, {10}^{11})$. Give the last 9 digits of your answer.
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# --hints--
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`totientSum()` should return `754862080`.
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```js
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assert.strictEqual(totientSum(), 754862080);
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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 totientSum() {
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return true;
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}
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totientSum();
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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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