# A095998 (b-file synthesized from sequence entry)
1 0
2 1
3 5
4 2
5 34
6 324
7 2988
8 28944
9 300816
10 3371040
11 793440
12 49438080
13 1121696640
14 21930773760
15 416139897600
16 7965912729600
17 156343306291200
18 3169866941337600
19 66629845591142400
20 1454242012231680000