simplify factorials: $\frac{(k-1)!}{(k+2)!}$
34374
Simplifying factorials: $\frac{(n-1)!}{(n-2)!}$
69228
Factorial of 0 - a convenience?
146305
Simplify sum of factorials with mathematical induction
45645
Using permutation or otherwise, prove that $\frac{(n^2)!}{(n!)^n}$ is an integer,where $n$ is a positive integer.
102542
Is there a way to reverse factorials?
129801
Finding a closed form for $\sum^{n}_{k=1} \frac{k}{(k+1)!} $
118024
Simplify the expression $\binom{n}{0}+\binom{n+1}{1}+\binom{n+2}{2}+\cdots +\binom{n+k}{k}$
482
Express $1 + \frac {1}{2} \binom{n}{1} + \frac {1}{3} \binom{n}{2} + \dotsb + \frac{1}{n + 1}\binom{n}{n}$ in a simplifed form
102738
Show that $e^n>\frac{(n+1)^n}{n!}$ without using induction.
118140
Prove that $ \frac{n(n-1)(n-k+1)}{k(k-1)\cdots1} = \frac{n!}{(n-1)!k!}$
106888
Factorial identity $n!=1+(1-1/1!)n+(1-1/1!+1/2!)n(n-1)+\cdots$
135218
Closed Form for Factorial Sum
154082
Product of factorials divided by factorial to produce perfect square
14540
Any shortcut to calculate factorial of a number (Without calculator or n to 1)?
9920
$(n^2 - 1)!$ is a multiple of $(n!)^n$
120913
How would you write a non-recursive algorithm to calculate factorials?
58589
On the factorial equations $A! B! =C!$ and $A!B!C! = D!$