# A354312 (b-file synthesized from sequence entry)
0 1
1 0
2 2
3 9
4 48
5 315
6 2496
7 22491
8 223728
9 2437371
10 28931040
11 371291283
12 5111412120
13 75014135235
14 1168157451384
15 19228202401635
16 333378840718944
17 6069073767712587
18 115683487658404272
19 2303091818149762899
20 47784447190060311240
21 1031179733234906055507