def f(n, i=1, res=0):
    res += i ** 3
    if i == n:
        return res
    return f(n, i+1, res)
print(f(3))

>>> def f(n):
...     assert n > 0
...     if n > 1:
...         return n ** 3 + f(n - 1)
...     return 1
... 
>>> f(3)
36
>>> f(2)
9
>>> f(1)
1
>>> f(0)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 2, in f
AssertionError
>>>

reduce(lambda x, res: x+res, [i**3 for i in range(1, 10)])