Warren Brown
9/16/2003 9:16:00 PM
Hal,
> Unfortunately, I can't remember exactly how
> it works.
>
> There are formulae that involve (n-k)!,
> perhaps in the denominator, I can't recall.
> And in the degenerate case where n=k,
> "common sense" tells us that we get the
> right answer if 0! is arbitrarily defined
> to be 1. So we do that.
Pretty much any way you define the factorial function, you always end up
with some form of the relationship:
X! = X * (X - 1)!
Or, put another way:
(X - 1)! = X! / X
So, for X == 1:
0! = 1! / 1
- Warren Brown