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  1. #include <stdio.h>
  2. //a{n} = -6a{n-1} -9a{n-2}, a{1}=1, a{2}=2(再帰なし版)
  3.  
  4. int main(void) {
  5.     int n = 4;
  6.     int a, b = 2, c = 1; 
  7.     for(int i = 3; i <= n; i++){
  8.         a = -6*b -9*c;
  9.         c = b;
  10.         b = a;
  11.     }
  12.     printf("数列a%dの値は%d\n", n, a);
  13. 	return 0;
  14. }
  15.  
  16.  
Success #stdin #stdout 0s 5320KB
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Standard input is empty
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数列a4の値は108
https://ideone.com/24WtCK
language:
C (gcc 8.3)
created:
13 days ago
visibility:
public

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