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										 |  |  |  | title: '问题 132:大纯元数因子' | 
					
						
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										 |  |  |  | challengeType: 5 | 
					
						
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										 |  |  |  | forumTopicId: 301760 | 
					
						
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										 |  |  |  | dashedName: problem-132-large-repunit-factors | 
					
						
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										 |  |  |  | # --description--
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										 |  |  |  | 完全由 1 组成的数字称为纯元数(repunit)。 我们定义 $R(k)$ 为长度 $k$ 的纯元数。 | 
					
						
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										 |  |  |  | 例如 $R(10) = 1111111111 = 11 × 41 × 271 × 9091$,则其素数因子的和为 9414。 | 
					
						
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										 |  |  |  | 求 $R({10}^9)$ 的前 40 个素数因子的和。 | 
					
						
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										 |  |  |  | # --hints--
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										 |  |  |  | `largeRepunitFactors()` 应该返回 `843296`。 | 
					
						
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							|  |  |  |  | ```js | 
					
						
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										 |  |  |  | assert.strictEqual(largeRepunitFactors(), 843296); | 
					
						
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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 largeRepunitFactors() { | 
					
						
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							|  |  |  |  |   return true; | 
					
						
							|  |  |  |  | } | 
					
						
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										 |  |  |  | largeRepunitFactors(); | 
					
						
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										 |  |  |  | ``` | 
					
						
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										 |  |  |  | # --solutions--
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										 |  |  |  | ```js | 
					
						
							|  |  |  |  | // solution required | 
					
						
							|  |  |  |  | ``` |