hdu 2047 阿牛的EOF牛肉串

#include <iostream>using namespace std;int main(){   int n;    long long num[40] = {0,3,8};    for(int i=3;i<40;i++)    {        num[i] = (num[i-2]+num[i-1])*2;    }    while(cin>>n)    {        cout<<num[n]<<endl;    }    return 0;}