Python Program to Find Sum of Natural Numbers Using Recursion

In this program, you'll learn to find the sum of natural numbers using recursive function.

To understand this example, you should have the knowledge of following Python programming topics:

In the program below, we've used a recursive function recur_sum() to compute the sum up to the given number.

Source Code

# Python program to find the sum of natural numbers up to n using recursive function

def recur_sum(n):
   """Function to return the sum
   of natural numbers using recursion"""
   if n <= 1:
       return n
   else:
       return n + recur_sum(n-1)

# change this value for a different result
num = 16

# uncomment to take input from the user
#num = int(input("Enter a number: "))

if num < 0:
   print("Enter a positive number")
else:
   print("The sum is",recur_sum(num))

Output

The sum is 136

Note: To test the program, change the value of num. Try negative numbers as well.