Program output for loop

Question

 

//Write a program in C# Sharp to display the sum of the series [ 1+x+x^2/2!+x^3/3!+....]

int x = int.Parse(Console.ReadLine());

int n = int.Parse(Console.ReadLine());

int sum = 1 + x;

int top;

for (int i = 2; i <= n; i++)

{

top = x ^ i;

sum = sum + top;

}

Console.WriteLine(sum);

 

Not able to proceed further. pls help. Also can we use X^i for powering a number?

 

My main doubt is how can i put factorial also in the above loop...

I see many answers in google for the above program. but not able to understand. can someone help with using the above code i did.