#include <stdio.h>
//練習問題F
 
int func(int n){
    int a=-1;
    int i;
    for(i = 0; i < n; i++){
       a = 3*func(n-1)+5;
   }
   return a;
}
int main(void) {
	int n = 3;
    printf("数列anについて, n=%dのときの値は%d\n", n
, func
(n
)); 	return 0;
}
 
				I2luY2x1ZGUgPHN0ZGlvLmg+Ci8v57e057+S5ZWP6aGMRgoKaW50IGZ1bmMoaW50IG4pewogICAgaW50IGE9LTE7CiAgICBpbnQgaTsKICAgIGZvcihpID0gMDsgaSA8IG47IGkrKyl7CiAgICAgICBhID0gMypmdW5jKG4tMSkrNTsKICAgfQogICByZXR1cm4gYTsKfQppbnQgbWFpbih2b2lkKSB7CglpbnQgbiA9IDM7CiAgICBwcmludGYoIuaVsOWIl2Fu44Gr44Gk44GE44GmLCBuPSVk44Gu44Go44GN44Gu5YCk44GvJWRcbiIsIG4sIGZ1bmMobikpOwoJcmV0dXJuIDA7Cn0K