# A118211 (b-file synthesized from sequence entry)
1 1
2 1
3 2
4 6
5 8
6 40
7 720
8 5040
9 8064
10 120960
11 3628800
12 4435200
13 479001600
14 2075673600
15 17435658240
16 1307674368000
17 634023936000
18 10162497945600
19 6402373705728000
20 17377871486976000
21 810967336058880000