prac 4 ex 4

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

namespace _4._4
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.Write("Введите точность e: ");
            double e = double.Parse(Console.ReadLine());
            double a = 1, s = 0;
            int i = 2;
            while (Math.Abs(a) >= e)
            {
                s += a;
                a /= Math.Pow(i, 2) - 1;
                i++;
            }
            Console.Write("{0:f6}", s);
            Console.ReadKey();
        }
    }
}