Calculate the sum of the positive integers of N+(N-2)+(N-4)… (until N-x =< 0)

Calculate the sum of the positive integers of N+(N-2)+(N-4)… (until N-x =< 0).

Test Data:

sum_series(6) -> 12

sum_series(10) -> 30

def sum_series(N):
    if N < 1:
        return 0
    else:
        return N + sum_series(N - 2)

# test
print(sum_series(6))     # 12
print(sum_series(10))    # 30

See also

https://www.w3resource.com/python-exercises/data-structures-and-algorithms/python-recursion-exercise-7.php