# A110371 (b-file synthesized from sequence entry)
1 2
2 4
3 20
4 168
5 2016
6 31680
7 617760
8 14414400
9 392071680
10 12189864960
11 426645273600
12 16606346803200
13 711700577280000
14 33307587016704000
15 1690360041097728000
16 92472637542405120000
17 5425061402487767040000
18 339780161524233830400000
19 22629358757513973104640000