# A187746 (b-file synthesized from sequence entry)
0 1
1 2
2 13
3 100
4 984
5 11712
6 163200
7 2603520
8 46771200
9 934133760
10 20530298880
11 492355584000
12 12793813401600
13 358063276032000
14 10737974299852800
15 343513154086502400
16 11676590580695040000
17 420271561157640192000
18 15967576932074127360000