65 lines
1.1 KiB
Markdown
65 lines
1.1 KiB
Markdown
---
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id: 5900f5131000cf542c510024
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challengeType: 5
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title: 'Problem 421: Prime factors of n15+1'
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---
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## Description
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<section id='description'>
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Numbers of the form n15+1 are composite for every integer n > 1.
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For positive integers n and m let s(n,m) be defined as the sum of the distinct prime factors of n15+1 not exceeding m.
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E.g. 215+1 = 3×3×11×331.
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So s(2,10) = 3 and s(2,1000) = 3+11+331 = 345.
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Also 1015+1 = 7×11×13×211×241×2161×9091.
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So s(10,100) = 31 and s(10,1000) = 483.
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Find ∑ s(n,108) for 1 ≤ n ≤ 1011.
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</section>
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## Instructions
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<section id='instructions'>
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</section>
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## Tests
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<section id='tests'>
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```yml
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tests:
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- text: <code>euler421()</code> should return 2304215802083466200.
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testString: assert.strictEqual(euler421(), 2304215802083466200, '<code>euler421()</code> should return 2304215802083466200.');
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```
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</section>
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## Challenge Seed
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<section id='challengeSeed'>
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<div id='js-seed'>
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```js
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function euler421() {
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// Good luck!
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return true;
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}
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euler421();
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```
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</div>
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</section>
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## Solution
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<section id='solution'>
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```js
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// solution required
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```
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</section>
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