How to organize a function that computes the fibonacci sequence

[depasqualen]

I am trying to create a function that prints the first 4 numbers in the fibonacci sequence, the first 10 numbers in the fibonacci sequence, and then "the first -4" numbers in the fibonacci sequence. The "-4" numbers in the fibonacci sequence should return an empty list because there is no "-4" numbers in the sequence. I need the function to print the 3 lists as an end result in the main() function. Here is my code so far, I'm new to functions so any help would be appreciated.

def F(n):
    if n == 0: return 0
    elif n ==1: return 1
    else: return F(n-1)+F(n-2)
main():
    print F(4)
    print F(10)
    print F(-4)
 
 

[bvdet]

First, you have to modify your function F() to accommodate negative integers. According to Wikipedia, the calculation can be generalized with this formula:

F[-n] = (-1)**(n+1)*F[n]

So, you would calculate the number for F[n] and apply it in the above equation for the negative index.

Print a range of numbers using the built-in range function.

>>> print ("[%s]" % (", ".join([str(F(n)) for n in range(-4,11)])))
[-3, 2, -1, 1, 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55]
>>> 

[depasqualen]

I don't need it to find the negative numbers, I need the -4 to return as an empty list. the output should look like this

[0, 1, 1, 2]
[0, 1, 1, 2, 3, 5, 8, 13, 21, 34]
[]

[bvdet]

According to the problem you presented, you need to show the first -4 numbers. This means to me one of the following:

>>> range(0, -4, -1)
[0, -1, -2, -3]
>>> range(-1, -5, -1)
[-1, -2, -3, -4]
>>> 

If my understanding is wrong, you have your answer.