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								---
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								id: 5900f4ff1000cf542c510011
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								title: 'Problem 402: Integer-valued polynomials'
							 
						 
					
						
							
								
									
										
										
										
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								challengeType: 5
							 
						 
					
						
							
								
									
										
										
										
											2019-08-05 09:17:33 -07:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								forumTopicId: 302070
							 
						 
					
						
							
								
									
										
										
										
											2021-01-13 03:31:00 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								dashedName: problem-402-integer-valued-polynomials
							 
						 
					
						
							
								
									
										
										
										
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								---
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
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								# --description--
  
						 
					
						
							
								
									
										
										
										
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								It can be shown that the polynomial $n^4 + 4n^3 + 2n^2 + 5n$ is a multiple of 6 for every integer $n$. It can also be shown that 6 is the largest integer satisfying this property.
							 
						 
					
						
							
								
									
										
										
										
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								Define $M(a, b, c)$ as the maximum $m$ such that $n^4 + an^3 + bn^2 + cn$ is a multiple of $m$ for all integers $n$. For example, $M(4, 2, 5) = 6$.
							 
						 
					
						
							
								
									
										
										
										
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								Also, define $S(N)$ as the sum of $M(a, b, c)$ for all $0 <  a, b, c ≤ N$.
							 
						 
					
						
							
								
									
										
										
										
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								We can verify that $S(10) = 1\\,972$ and $S(10\\,000) = 2\\,024\\,258\\,331\\,114$.
							 
						 
					
						
							
								
									
										
										
										
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								Let $F_k$ be the Fibonacci sequence:
							 
						 
					
						
							
								
									
										
										
										
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								-  $F_0 = 0$, $F_1 = 1$ and 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								-  $F_k = F_{k - 1} + F_{k - 2}$ for $k ≥ 2$. 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								Find the last 9 digits of $\sum S(F_k)$ for $2 ≤ k ≤ 1\\,234\\,567\\,890\\,123$.
							 
						 
					
						
							
								
									
										
										
										
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								# --hints--
  
						 
					
						
							
								
									
										
										
										
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								`integerValuedPolynomials()`  should return `356019862` . 
						 
					
						
							
								
									
										
										
										
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								```js
							 
						 
					
						
							
								
									
										
										
										
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								assert.strictEqual(integerValuedPolynomials(), 356019862);
							 
						 
					
						
							
								
									
										
										
										
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								```
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
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								# --seed--
  
						 
					
						
							
								
									
										
										
										
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								## --seed-contents--
  
						 
					
						
							
								
									
										
										
										
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								```js
							 
						 
					
						
							
								
									
										
										
										
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								function integerValuedPolynomials() {
							 
						 
					
						
							
								
									
										
										
										
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								  return true;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								}
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
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								integerValuedPolynomials();
							 
						 
					
						
							
								
									
										
										
										
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								```
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
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								# --solutions--
  
						 
					
						
							
								
									
										
										
										
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								```js
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								// solution required
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								```