0! = 1
1! = 1
2! = 2
3! = 6
4! = 24
5! = 120
6! = 720
7! = 5040
8! = 40320
9! = 362880
10! = 3.6288e+006
11! = 3.99168e+007
12! = 4.79002e+008
13! = 6.22702e+009
14! = 8.71783e+010
15! = 1.30767e+012
