Incomplete drawing display

[Bollie15]

Here is my code to solve "Unique Binary Search Trees" problem.

def fn(lo,hi):
    if lo >= hi:
        return 1
    tot = 0
    for i in range(lo, hi+1):
        tot += fn(lo,i-1)*fn(i+1,hi)
    return tot

When I call fn(1, 4), it can draw picture(< maximun recursion), it can't draw the recursion tree completely no matter how I zoom in the broswer.

So I think you can set a button to download this entire picture quickly. By the way, I always get the screenshot to get a picture.
😋