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										 |  |  |  | title: 'Problem 187: Semiprimes' | 
					
						
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										 |  |  |  | challengeType: 5 | 
					
						
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										 |  |  |  | forumTopicId: 301823 | 
					
						
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										 |  |  |  | dashedName: problem-187-semiprimes | 
					
						
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										 |  |  |  | # --description--
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										 |  |  |  | A composite is a number containing at least two prime factors. For example, 15 = 3 × 5; 9 = 3 × 3; 12 = 2 × 2 × 3. | 
					
						
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										 |  |  |  | There are ten composites below thirty containing precisely two, not necessarily distinct, prime factors: 4, 6, 9, 10, 14, 15, 21, 22, 25, 26. | 
					
						
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										 |  |  |  | How many composite integers, n < 108, have precisely two, not necessarily distinct, prime factors? | 
					
						
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										 |  |  |  | # --hints--
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										 |  |  |  | `euler187()` should return 17427258. | 
					
						
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							|  |  |  |  | ```js | 
					
						
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										 |  |  |  | assert.strictEqual(euler187(), 17427258); | 
					
						
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										 |  |  |  | ``` | 
					
						
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										 |  |  |  | # --seed--
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							|  |  |  |  | ## --seed-contents--
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							|  |  |  |  | ```js | 
					
						
							|  |  |  |  | function euler187() { | 
					
						
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							|  |  |  |  |   return true; | 
					
						
							|  |  |  |  | } | 
					
						
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							|  |  |  |  | euler187(); | 
					
						
							|  |  |  |  | ``` | 
					
						
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										 |  |  |  | # --solutions--
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										 |  |  |  | ```js | 
					
						
							|  |  |  |  | // solution required | 
					
						
							|  |  |  |  | ``` |