Fibonacci Number Sequence Program in C#

The Fibonacci sequence is a series of numbers where each number is the sum of the two preceding ones, usually starting with 0 and 1. The sequence goes like this:

 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, ...  

If you need a specific Fibonacci number or want to know how to calculate it, then here's a simple C# program to generate the Fibonacci sequence up to a specified number of terms:

 using System;  
 class Fibonacci  
 {  
   static void Main()  
   {  
     Console.Write("Enter the number of terms in the Fibonacci sequence: ");  
     int terms = int.Parse(Console.ReadLine());  
     Console.WriteLine("Fibonacci Sequence:");  
     for (int i = 0; i < terms; i++)  
     {  
       Console.Write(FibonacciNumber(i) + " ");  
     }  
   }  
   static int FibonacciNumber(int n)  
   {  
     if (n <= 1)  
       return n;  
     return FibonacciNumber(n - 1) + FibonacciNumber(n - 2);  
   }  
 }  

How it works:

1. Input: The program prompts the user to enter the number of terms they want in the Fibonacci sequence.
2. Fibonacci Calculation: The FibonacciNumber method calculates Fibonacci numbers recursively.
3. Output: The program prints the Fibonacci sequence up to the specified number of terms.

For larger numbers of terms, consider using an iterative approach to improve performance:

 static void Main()  
 {  
   Console.Write("Enter the number of terms in the Fibonacci sequence: ");  
   int terms = int.Parse(Console.ReadLine());  
   Console.WriteLine("Fibonacci Sequence:");  
   int a = 0, b = 1;  
   for (int i = 0; i < terms; i++)  
   {  
     Console.Write(a + " ");  
     int temp = a;  
     a = b;  
     b = temp + b;  
   }  
 }  

This iterative version is more efficient than the Recursive Approach for larger sequences. The is the Recursive Approach to calculate the Fibonacci number sequence

Thanks