# A356561 (b-file synthesized from sequence entry)
0 1
1 1
2 4
3 18
4 204
5 1260
6 37440
7 299880
8 11002320
9 204860880
10 6618628800
11 92924647200
12 8181137764800
13 124123075876800
14 7211104918617600
15 288085376346768000
16 14964000305173920000
17 340302035937191328000
18 42619767305209750656000