Find Fibonacci Series Without Using Recursion in Python

When it is required to find the Fibonacci series without using recursion technique, the input is taken from the user, and a ‘while’ loop is used to get the numbers in the sequence.

Example

Below is a demonstration for the same −

 Live Demo

first_num = int(input("Enter the first number of the fibonacci series... "))
second_num = int(input("Enter the second number of the fibonacci series... "))
num_of_terms = int(input("Enter the number of terms... "))
print(first_num,second_num)
print("The numbers in fibonacci series are : ")
while(num_of_terms-2):
   third_num = first_num + second_num
   first_num=second_num
   second_num=third_num
   print(third_num)
   num_of_terms=num_of_terms-1

Output

Enter the first number of the fibonacci series... 2
Enter the second number of the fibonacci series... 8
Enter the number of terms... 8
2 8
The numbers in fibonacci series are :
10
18
28
46
74
120

Explanation

• The first number and second number inputs are taken from the user.
• The number of terms is also taken from the user.
• The first and the second numbers are printed on the console.
• A while loop begins, and the below takes place −
• The first and second numbers are added and assigned to a third number.
• The second number is assigned to the third number.
• The third number is assigned to the second number.
• The third number is printed on the console.
• The number of terms is decremented by 1.