1304因子求和

#include <stdio.h>
int main(int argc,char const *argv[])
{
    // 0 0 1 1 2 4
    int n;
    scanf("%d",&n);
    int i;
    int a=0,b=0,c=1;
    int term=1;
    int sum=0;
    n-=2;
    while(n>0