# A100404 (b-file synthesized from sequence entry)
0 2
1 1
2 6
3 24
4 168
5 1320
6 12960
7 146160
8 1895040
9 27578880
10 446342400
11 7943443200
12 154238515200
13 3244277836800
14 73491299481600
15 1783667837952000
16 46176597282816000
17 1270159805730816000
18 36992915271696384000
19 1137260043722170368000
20 36802508677688033280000