> #include "stdio.h"
> int main()
> { int n;
>   double e=0;
>   double sum=1;
>   printf("n e\n- -----------\n");
>   for(n=0;n<=9;n++){
>       if(n!=0)sum=n*sum;
>       e+=1/sum;
>       printf("%d %.9lf\n",n,e);
>   }
>   return 0;
> }