45 lines
756 B
Markdown
45 lines
756 B
Markdown
---
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id: 5900f4ed1000cf542c50ffff
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title: 'Problem 383: Divisibility comparison between factorials'
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challengeType: 5
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forumTopicId: 302047
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dashedName: problem-383-divisibility-comparison-between-factorials
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---
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# --description--
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Let f5(n) be the largest integer x for which 5x divides n.
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For example, f5(625000) = 7.
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Let T5(n) be the number of integers i which satisfy f5((2·i-1)!) < 2·f5(i!) and 1 ≤ i ≤ n. It can be verified that T5(103) = 68 and T5(109) = 2408210.
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Find T5(1018).
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# --hints--
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`euler383()` should return 22173624649806.
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```js
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assert.strictEqual(euler383(), 22173624649806);
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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 euler383() {
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return true;
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}
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euler383();
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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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