43 lines
		
	
	
		
			818 B
		
	
	
	
		
			Markdown
		
	
	
	
	
	
		
		
			
		
	
	
			43 lines
		
	
	
		
			818 B
		
	
	
	
		
			Markdown
		
	
	
	
	
	
|   | --- | |||
|  | id: 5900f45d1000cf542c50ff70 | |||
|  | title: 'Problem 241: Perfection Quotients' | |||
|  | challengeType: 5 | |||
|  | forumTopicId: 301888 | |||
|  | dashedName: problem-241-perfection-quotients | |||
|  | --- | |||
|  | 
 | |||
|  | # --description--
 | |||
|  | 
 | |||
|  | For a positive integer n, let σ(n) be the sum of all divisors of n, so e.g. σ(6) = 1 + 2 + 3 + 6 = 12. | |||
|  | 
 | |||
|  | A perfect number, as you probably know, is a number with σ(n) = 2n. | |||
|  | 
 | |||
|  | Let us define the perfection quotient of a positive integer asp(n)= σ(n)n . Find the sum of all positive integers n ≤ 1018 for which p(n) has the form k + 1⁄2, where k is an integer. | |||
|  | 
 | |||
|  | # --hints--
 | |||
|  | 
 | |||
|  | `euler241()` should return 482316491800641150. | |||
|  | 
 | |||
|  | ```js | |||
|  | assert.strictEqual(euler241(), 482316491800641150); | |||
|  | ``` | |||
|  | 
 | |||
|  | # --seed--
 | |||
|  | 
 | |||
|  | ## --seed-contents--
 | |||
|  | 
 | |||
|  | ```js | |||
|  | function euler241() { | |||
|  | 
 | |||
|  |   return true; | |||
|  | } | |||
|  | 
 | |||
|  | euler241(); | |||
|  | ``` | |||
|  | 
 | |||
|  | # --solutions--
 | |||
|  | 
 | |||
|  | ```js | |||
|  | // solution required | |||
|  | ``` |