#include <stdio.h>
//a{n+1} = -2a{n} + 4, a{0}=2(再帰あり版)
int rec(int n){
int an=2;
for(int i=0;i<n;i++){
an=-2*an+4;
}
return an;
}
int main(void) {
int n,m;
printf("数列a%dの値は%d\n", n
, rec
(n
)); printf("数列a%dの値は%d\n", m
, rec
(m
)); return 0;
}
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