45 lines
		
	
	
		
			642 B
		
	
	
	
		
			Markdown
		
	
	
	
	
	
		
		
			
		
	
	
			45 lines
		
	
	
		
			642 B
		
	
	
	
		
			Markdown
		
	
	
	
	
	
|   | --- | ||
|  | id: 5900f52c1000cf542c51003e | ||
|  | title: 'Problem 447: Retractions C' | ||
|  | challengeType: 5 | ||
|  | forumTopicId: 302119 | ||
|  | dashedName: problem-447-retractions-c | ||
|  | --- | ||
|  | 
 | ||
|  | # --description--
 | ||
|  | 
 | ||
|  | For every integer n>1, the family of functions fn,a,b is defined | ||
|  | 
 | ||
|  | by fn,a,b(x)≡ax+b mod n for a,b,x integer and 0 | ||
|  | 
 | ||
|  | F(N)=∑R(n) for 2≤n≤N. F(107)≡638042271 (mod 1 000 000 007). | ||
|  | 
 | ||
|  | Find F(1014) (mod 1 000 000 007). | ||
|  | 
 | ||
|  | # --hints--
 | ||
|  | 
 | ||
|  | `euler447()` should return 530553372. | ||
|  | 
 | ||
|  | ```js | ||
|  | assert.strictEqual(euler447(), 530553372); | ||
|  | ``` | ||
|  | 
 | ||
|  | # --seed--
 | ||
|  | 
 | ||
|  | ## --seed-contents--
 | ||
|  | 
 | ||
|  | ```js | ||
|  | function euler447() { | ||
|  | 
 | ||
|  |   return true; | ||
|  | } | ||
|  | 
 | ||
|  | euler447(); | ||
|  | ``` | ||
|  | 
 | ||
|  | # --solutions--
 | ||
|  | 
 | ||
|  | ```js | ||
|  | // solution required | ||
|  | ``` |