# A141052 (b-file synthesized from sequence entry)
2 1
3 4
4 21
5 130
6 930
7 7560
8 68880
9 695520
10 7711200
11 93139200
12 1217462400
13 17124307200
14 257902444800
15 4140968832000
16 70614415872000
17 1274546617344000
18 24275666967552000
19 486580401635328000
20 10238462617743360000
21 225651661258383360000
22 5198503365971435520000