Practicum5-III-2

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp2
{
    class Program
    {
        static double F_n(double n)
        {
            if (n==1) { return 5; }
            else { return (F_n(n - 1)) / (n * n + n + 1); }
        }
        static void Main()
        {
            Console.Write("Please enter the n=");
            double n = double.Parse(Console.ReadLine());
            Console.WriteLine("{0}",F_n(n));
        }
    }
}