Sum of n natural numbers

Title: Sum of n natural numbers

Natural numbers are

1, 2,3,4,…………infinity

Sum of 5 natural numbers are

1+2+3+4+5=15

Program-1:

n=int(input("Enter n value\n"))

sum=0

for i in range(1,n+1):

    sum=sum+i

print("The sum of ",n," natural numbers is ",sum)

Output:

Enter n value

5

The sum of  5  natural numbers is  15

Program-2:

n=int(input("Enter n value\n"))

sum=0

for i in range(n,0,-1):

    sum=sum+i

print("The sum of ",n," natural numbers is ",sum)

Output:

Enter n value

5

The sum of  5  natural numbers is  15