#include <stdio.h>
//a{n} = -6a{n-1} -9a{n-2}, a{1}=1, a{2}=2(再帰あり版)
int c;
int rec(int n){
	c++;
	if(n==1){
		return 1;
	}
	else if(n==2){
		return 2;
	}
	else{
		return -6*rec(n-1)-9*rec(n-2);
	}
 
 
}
 
int main(void) {
    int n = 5;
    printf("数列a%dの値は%d\n", n
, rec
(n
));     printf("このときのrecの呼び出し回数は%d",c
); 	return 0;
}
 
 
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