program to Print Sum of factorial Series in C

C# program to Print Sum of factorial Series

Program Statement:

Write a program to display the sum of the following series.

2/1! + 4/3! + 6/5! + 8/7! + 10/9! + . . . + n/(n-1)!

Solution:

 public class factorial
 {
 int n;
 public void ser()
 {
 double f, sum = 2, res = 1, up = 2;

 Console.WriteLine(" Series = 2/1! + 4/3! + 6/5! + 8/7! + 10/9! + . . . + n/(n-1)!");
 Console.WriteLine();
 Console.Write(" Enter ending point : ");
 n = Convert.ToInt16(Console.ReadLine());

 for (int i = 2; i <= n; i++)
 {
 if (i % 2 == 1)
 {
 f = 1;
 for (int x = i; x > 0; x--)
 { f = f * x; }
 up = up + 2;
 res = up / f;
 sum = sum + res;
 }
 }
 Console.WriteLine(" Sum : {0} ", sum);
 Console.WriteLine();
 }
 }