47 lines
		
	
	
		
			807 B
		
	
	
	
		
			Markdown
		
	
	
	
	
	
		
		
			
		
	
	
			47 lines
		
	
	
		
			807 B
		
	
	
	
		
			Markdown
		
	
	
	
	
	
|   | --- | ||
|  | id: 5900f50f1000cf542c510021 | ||
|  | title: 'Problem 418: Factorisation triples' | ||
|  | challengeType: 5 | ||
|  | forumTopicId: 302087 | ||
|  | dashedName: problem-418-factorisation-triples | ||
|  | --- | ||
|  | 
 | ||
|  | # --description--
 | ||
|  | 
 | ||
|  | Let n be a positive integer. An integer triple (a, b, c) is called a factorisation triple of n if: 1 ≤ a ≤ b ≤ c | ||
|  | 
 | ||
|  | a·b·c = n. | ||
|  | 
 | ||
|  | Define f(n) to be a + b + c for the factorisation triple (a, b, c) of n which minimises c / a. One can show that this triple is unique. | ||
|  | 
 | ||
|  | For example, f(165) = 19, f(100100) = 142 and f(20!) = 4034872. | ||
|  | 
 | ||
|  | Find f(43!). | ||
|  | 
 | ||
|  | # --hints--
 | ||
|  | 
 | ||
|  | `euler418()` should return 1177163565297340400. | ||
|  | 
 | ||
|  | ```js | ||
|  | assert.strictEqual(euler418(), 1177163565297340400); | ||
|  | ``` | ||
|  | 
 | ||
|  | # --seed--
 | ||
|  | 
 | ||
|  | ## --seed-contents--
 | ||
|  | 
 | ||
|  | ```js | ||
|  | function euler418() { | ||
|  | 
 | ||
|  |   return true; | ||
|  | } | ||
|  | 
 | ||
|  | euler418(); | ||
|  | ``` | ||
|  | 
 | ||
|  | # --solutions--
 | ||
|  | 
 | ||
|  | ```js | ||
|  | // solution required | ||
|  | ``` |