#include <stdio.h>
//a{n+1} = -2a{n} + 4, a{0}=2(再帰なし版)
int main(void) {
int n = 4;
int an = 2;
int i;
for(i = 0; n > i; i++){
an = -2*an+4;
}
printf("数列a%dの値は%d\n", n
, an
);
return 0;
}
I2luY2x1ZGUgPHN0ZGlvLmg+Ci8vYXtuKzF9ID0gLTJhe259ICsgNCwgYXswfT0yKOWGjeW4sOOBquOBl+eJiCkKaW50IG1haW4odm9pZCkgewogICAgaW50IG4gPSA0OwogICAgaW50IGFuID0gMjsKICAgIGludCBpOwogICAgZm9yKGkgPSAwOyBuID4gaTsgaSsrKXsKICAgIAlhbiA9IC0yKmFuKzQ7CiAgICB9CgogICAgcHJpbnRmKCLmlbDliJdhJWTjga7lgKTjga8lZFxuIiwgbiwgYW4pOwoKCXJldHVybiAwOwp9Cgo=