# A229039 (b-file synthesized from sequence entry)
0 1
1 3
2 7
3 24
4 108
5 600
6 3960
7 30240
8 262080
9 2540160
10 27216000
11 319334400
12 4071513600
13 56043187200
14 828193766400
15 13076743680000
16 219689293824000
17 3912561709056000
18 73627297615872000
19 1459741204905984000
20 30411275102208000000
21 664182248232222720000