ee1e8abd87
* feat(tools): add seed/solution restore script * chore(curriculum): remove empty sections' markers * chore(curriculum): add seed + solution to Chinese * chore: remove old formatter * fix: update getChallenges parse translated challenges separately, without reference to the source * chore(curriculum): add dashedName to English * chore(curriculum): add dashedName to Chinese * refactor: remove unused challenge property 'name' * fix: relax dashedName requirement * fix: stray tag Remove stray `pre` tag from challenge file. Signed-off-by: nhcarrigan <nhcarrigan@gmail.com> Co-authored-by: nhcarrigan <nhcarrigan@gmail.com>
41 lines
761 B
Markdown
41 lines
761 B
Markdown
---
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id: 5900f4451000cf542c50ff57
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title: 问题216：调查2n2-1形式的数字的素数
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challengeType: 5
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videoUrl: ''
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dashedName: problem-216-investigating-the-primality-of-numbers-of-the-form-2n2-1
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---
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# --description--
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考虑形式为t（n）= 2n2-1的数字t（n），其中n> 1.第一个这样的数字是7,17,31,49,71,97,127和161.事实证明只有49 = 7 \* 7和161 = 7 \* 23不是素数。对于n≤10000，有2202个数字t（n）是素数。
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对于n≤50,000,000，有多少个数t（n）是素数？
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# --hints--
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`euler216()`应该返回5437849。
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```js
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assert.strictEqual(euler216(), 5437849);
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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 euler216() {
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return true;
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}
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euler216();
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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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