Anyway, this denominator right over here can be rewritten as k factorial. This right over here can be rewritten as k factorial. Is there any way to rewrite this numerator in terms of factorials? If we were to write n factorial, let me see how we can write this. If we were to write n factorial, n factorial would be equal to n times n minus 1 times n minus 2, all the way down to 1. That's kind of what we want. We just want the first k terms of it.