1 #include <bits/stdc++.h>
 2 using namespace std;
 3 inline double gcd(int n)
 4 {
 5     int sum=1;
 6     for(int i=1;i<=n;i++)
 7         sum*=i;
 8     return sum;
 9 }
10 int main()
11 {
12     cout<<'n'<<" "<<'e'<<endl;
13     cout<<"- -----------"<<endl;
14     cout<<0<<" "<<1<<endl;
15     cout<<1<<" "<<2<<endl;
16     cout<<2<<" "<<2.5<<endl;
17     double sum=2.5;
18     for(int i=3;i<=9;i++)
19     {
20         sum+=(1.0/(double)gcd(i));
21         printf("%d %.9lf\n",i,sum);
22     }
23     return 0;
24 }