47 lines
		
	
	
		
			742 B
		
	
	
	
		
			Markdown
		
	
	
	
	
	
		
		
			
		
	
	
			47 lines
		
	
	
		
			742 B
		
	
	
	
		
			Markdown
		
	
	
	
	
	
|   | --- | ||
|  | id: 5900f52c1000cf542c51003f | ||
|  | title: 'Problem 448: Average least common multiple' | ||
|  | challengeType: 5 | ||
|  | forumTopicId: 302120 | ||
|  | dashedName: problem-448-average-least-common-multiple | ||
|  | --- | ||
|  | 
 | ||
|  | # --description--
 | ||
|  | 
 | ||
|  | The function lcm(a,b) denotes the least common multiple of a and b. | ||
|  | 
 | ||
|  | Let A(n) be the average of the values of lcm(n,i) for 1≤i≤n. | ||
|  | 
 | ||
|  | E.g: A(2)=(2+2)/2=2 and A(10)=(10+10+30+20+10+30+70+40+90+10)/10=32. | ||
|  | 
 | ||
|  | Let S(n)=∑A(k) for 1≤k≤n. S(100)=122726. | ||
|  | 
 | ||
|  | Find S(99999999019) mod 999999017. | ||
|  | 
 | ||
|  | # --hints--
 | ||
|  | 
 | ||
|  | `euler448()` should return 106467648. | ||
|  | 
 | ||
|  | ```js | ||
|  | assert.strictEqual(euler448(), 106467648); | ||
|  | ``` | ||
|  | 
 | ||
|  | # --seed--
 | ||
|  | 
 | ||
|  | ## --seed-contents--
 | ||
|  | 
 | ||
|  | ```js | ||
|  | function euler448() { | ||
|  | 
 | ||
|  |   return true; | ||
|  | } | ||
|  | 
 | ||
|  | euler448(); | ||
|  | ``` | ||
|  | 
 | ||
|  | # --solutions--
 | ||
|  | 
 | ||
|  | ```js | ||
|  | // solution required | ||
|  | ``` |