# A375806 (b-file synthesized from sequence entry)
0 1
1 2
2 6
3 30
4 192
5 1520
6 14220
7 153720
8 1881600
9 25728192
10 388402560
11 6415960320
12 115078138560
13 2227056923520
14 46247253212160
15 1025696098627200
16 24195406204569600
17 604862279807385600
18 15973029429800002560
19 444299711254300661760
20 12983645995613669376000