# A013516 (b-file synthesized from sequence entry)
0 1
1 2
2 8
3 16
4 128
5 3840
6 15360
7 92160
8 1474560
9 185794560
10 3715891200
11 117964800
12 2831155200
13 51011754393600
14 13603134504960
15 8569974738124800
16 1371195958099968000
17 46620662575398912000
18 239763407530622976000