| 
									
										
										
										
											2018-09-30 23:01:58 +01:00
										 |  |  | --- | 
					
						
							|  |  |  | id: 5900f52c1000cf542c51003e | 
					
						
							|  |  |  | title: 'Problem 447: Retractions C' | 
					
						
							| 
									
										
										
										
											2020-11-27 19:02:05 +01:00
										 |  |  | challengeType: 5 | 
					
						
							| 
									
										
										
										
											2019-08-05 09:17:33 -07:00
										 |  |  | forumTopicId: 302119 | 
					
						
							| 
									
										
										
										
											2021-01-13 03:31:00 +01:00
										 |  |  | dashedName: problem-447-retractions-c | 
					
						
							| 
									
										
										
										
											2018-09-30 23:01:58 +01:00
										 |  |  | --- | 
					
						
							|  |  |  | 
 | 
					
						
							| 
									
										
										
										
											2020-11-27 19:02:05 +01:00
										 |  |  | # --description--
 | 
					
						
							| 
									
										
										
										
											2018-09-30 23:01:58 +01:00
										 |  |  | 
 | 
					
						
							| 
									
										
										
										
											2020-11-27 19:02:05 +01:00
										 |  |  | For every integer n>1, the family of functions fn,a,b is defined | 
					
						
							| 
									
										
										
										
											2018-09-30 23:01:58 +01:00
										 |  |  | 
 | 
					
						
							| 
									
										
										
										
											2020-11-27 19:02:05 +01:00
										 |  |  | by fn,a,b(x)≡ax+b mod n for a,b,x integer and 0 | 
					
						
							| 
									
										
										
										
											2018-09-30 23:01:58 +01:00
										 |  |  | 
 | 
					
						
							| 
									
										
										
										
											2020-11-27 19:02:05 +01:00
										 |  |  | F(N)=∑R(n) for 2≤n≤N. F(107)≡638042271 (mod 1 000 000 007). | 
					
						
							| 
									
										
										
										
											2018-09-30 23:01:58 +01:00
										 |  |  | 
 | 
					
						
							|  |  |  | Find F(1014) (mod 1 000 000 007). | 
					
						
							|  |  |  | 
 | 
					
						
							| 
									
										
										
										
											2020-11-27 19:02:05 +01:00
										 |  |  | # --hints--
 | 
					
						
							| 
									
										
										
										
											2018-09-30 23:01:58 +01:00
										 |  |  | 
 | 
					
						
							| 
									
										
										
										
											2020-11-27 19:02:05 +01:00
										 |  |  | `euler447()` should return 530553372. | 
					
						
							| 
									
										
										
										
											2018-09-30 23:01:58 +01:00
										 |  |  | 
 | 
					
						
							| 
									
										
										
										
											2020-11-27 19:02:05 +01:00
										 |  |  | ```js | 
					
						
							|  |  |  | assert.strictEqual(euler447(), 530553372); | 
					
						
							| 
									
										
										
										
											2018-09-30 23:01:58 +01:00
										 |  |  | ``` | 
					
						
							|  |  |  | 
 | 
					
						
							| 
									
										
										
										
											2020-11-27 19:02:05 +01:00
										 |  |  | # --seed--
 | 
					
						
							| 
									
										
										
										
											2018-09-30 23:01:58 +01:00
										 |  |  | 
 | 
					
						
							| 
									
										
										
										
											2020-11-27 19:02:05 +01:00
										 |  |  | ## --seed-contents--
 | 
					
						
							| 
									
										
										
										
											2018-09-30 23:01:58 +01:00
										 |  |  | 
 | 
					
						
							|  |  |  | ```js | 
					
						
							|  |  |  | function euler447() { | 
					
						
							| 
									
										
										
										
											2020-09-15 09:57:40 -07:00
										 |  |  | 
 | 
					
						
							| 
									
										
										
										
											2018-09-30 23:01:58 +01:00
										 |  |  |   return true; | 
					
						
							|  |  |  | } | 
					
						
							|  |  |  | 
 | 
					
						
							|  |  |  | euler447(); | 
					
						
							|  |  |  | ``` | 
					
						
							|  |  |  | 
 | 
					
						
							| 
									
										
										
										
											2020-11-27 19:02:05 +01:00
										 |  |  | # --solutions--
 | 
					
						
							| 
									
										
										
										
											2018-09-30 23:01:58 +01:00
										 |  |  | 
 | 
					
						
							|  |  |  | ```js | 
					
						
							|  |  |  | // solution required | 
					
						
							|  |  |  | ``` |