# A222470 (b-file synthesized from sequence entry)
1 1
2 2
3 4
4 12
5 52
6 288
7 1912
8 14720
9 128656
10 1257120
11 13571008
12 160337856
13 2057250112
14 28480825856
15 423097887616
16 6712604550144
17 113268081577216
18 2025400259289600
19 38256068763347968
20 761070574748380160