#include <stdio.h>
int rec(int n){
if(n==1){
return 1;
}
else if(n==2){
return 2;
}
else{
return -6*rec(n-1)-9*(n-2);
}
}
int main(void) {
int n = 4;
printf("数列a%dの値は%d\n",n
,rec
(n
)); return 0;
}
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