# A354303 (b-file synthesized from sequence entry)
0 1
1 1
2 4
3 18
4 576
5 2400
6 518400
7 12700800
8 541900800
9 65840947200
10 13168189440000
11 88519495680000
12 229442532802560000
13 19387894021816320000
14 2533351485517332480000
15 855006126362099712000000
16 437763136697395052544000000
17 1621968544942912438272000000