# A293487 (b-file synthesized from sequence entry)
0 1
1 1
2 0
3 6
4 24
5 120
6 720
7 5040
8 80640
9 725760
10 7257600
11 79833600
12 1437004800
13 18681062400
14 261534873600
15 5230697472000
16 104613949440000
17 1778437140480000
18 32011868528640000
19 729870602452992000
20 17030314057236480000
21 408727537373675520000
22 8992005822220861440000