# A073978 (b-file synthesized from sequence entry)
1 0
2 0
3 3
4 24
5 210
6 1620
7 9072
8 46656
9 262440
10 1594080
11 9843120
12 60466176
13 367960320
14 2210794560
15 13162730688
16 78328332288
17 468205557120
18 2810089946880
19 16894457846784
20 101559956668416
21 609954817881600
22 3659790885120000
23 21947909832446976
24 131621703842267136