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  1. #include <stdio.h>
  2. //a{n} = -6a{n-1} -9a{n-2}, a{1}=1, a{2}=2(再帰あり版)
  3. int rec(int n){
  4. 	if (n==1){
  5. 		return 1;
  6. 	}
  7. 	else if(n==2){
  8. 		return 2;
  9. 	}
  10. 	else {
  11. 		return -6*(n-1)-9*(n-2);
  12. 	}
  13.  
  14.  
  15. }
  16.  
  17. int main(void) {
  18.     int n = 4;
  19.     printf("数列a%dの値は%d\n", n, rec(n));
  20. 	return 0;
  21. }
  22.  
  23.  
Success #stdin #stdout 0s 5272KB
comments (?)
stdin 
Standard input is empty
stdout 
数列a4の値は-36
https://ideone.com/bhMUOD
language:
C (gcc 8.3)
created:
72 days ago
visibility:
public

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