43 lines
		
	
	
		
			613 B
		
	
	
	
		
			Markdown
		
	
	
	
	
	
		
		
			
		
	
	
			43 lines
		
	
	
		
			613 B
		
	
	
	
		
			Markdown
		
	
	
	
	
	
|   | --- | |||
|  | id: 5900f51e1000cf542c510030 | |||
|  | title: 'Problem 432: Totient sum' | |||
|  | challengeType: 5 | |||
|  | forumTopicId: 302103 | |||
|  | dashedName: problem-432-totient-sum | |||
|  | --- | |||
|  | 
 | |||
|  | # --description--
 | |||
|  | 
 | |||
|  | Let S(n,m) = ∑φ(n × i) for 1 ≤ i ≤ m. (φ is Euler's totient function) | |||
|  | 
 | |||
|  | You are given that S(510510,106 )= 45480596821125120. | |||
|  | 
 | |||
|  | Find S(510510,1011). Give the last 9 digits of your answer. | |||
|  | 
 | |||
|  | # --hints--
 | |||
|  | 
 | |||
|  | `euler432()` should return 754862080. | |||
|  | 
 | |||
|  | ```js | |||
|  | assert.strictEqual(euler432(), 754862080); | |||
|  | ``` | |||
|  | 
 | |||
|  | # --seed--
 | |||
|  | 
 | |||
|  | ## --seed-contents--
 | |||
|  | 
 | |||
|  | ```js | |||
|  | function euler432() { | |||
|  | 
 | |||
|  |   return true; | |||
|  | } | |||
|  | 
 | |||
|  | euler432(); | |||
|  | ``` | |||
|  | 
 | |||
|  | # --solutions--
 | |||
|  | 
 | |||
|  | ```js | |||
|  | // solution required | |||
|  | ``` |