# A007200 (b-file synthesized from sequence entry)
2 12
3 48
4 180
5 792
6 3444
7 15000
8 64932
9 280200
10 1204572
11 5159448
12 22043292
13 93952428
14 399711348
15 1697721852
16 7200873444
17 30500477676
18 129049335924
19 545436439536
20 2303305856916