66 lines
1.1 KiB
Markdown
66 lines
1.1 KiB
Markdown
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---
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id: 5
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localeTitle: 5900f4be1000cf542c50ffd0
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challengeType: 5
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title: 'Problem 337: Totient Stairstep Sequences'
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---
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## Description
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<section id='description'>
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Sea {a1, a2, ..., an} una secuencia entera de longitud n tal que:
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a1 = 6
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para todos 1 ≤ i <n: φ (ai) <φ (ai + 1) <ai < ai + 11
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Sea S (N) el número de tales secuencias con un ≤ N.
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Por ejemplo, S (10) = 4: {6}, {6, 8}, {6, 8, 9} y { 6, 10}.
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Podemos verificar que S (100) = 482073668 y S (10 000) mod 108 = 73808307.
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Encuentre S (20 000 000) mod 108.
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1 φ denota la función total de Euler.
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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>euler337()</code> debe devolver 85068035.
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testString: 'assert.strictEqual(euler337(), 85068035, "<code>euler337()</code> should return 85068035.");'
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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 euler337() {
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// Good luck!
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return true;
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}
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euler337();
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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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