# A145143 (b-file synthesized from sequence entry)
2 1
3 1
4 2
5 6
6 144
7 1200
8 9960
9 89040
10 1231776
11 18325440
12 280100160
13 4415368320
14 78497147520
15 1538731434240
16 32250825734400
17 708789321676800
18 16531867860480000
19 410557135229337600
20 10800330695046144000
21 298418233851795456000
22 8641298765266642944000