# A136783 (b-file synthesized from sequence entry)
1 1
2 4
3 20
4 112
5 660
6 3976
7 24180
8 147648
9 903140
10 5528504
11 33853220
12 207325392
13 1269787060
14 7777149416
15 47633751380
16 291750220768
17 1786933908740
18 10944758154264
19 67035370422020
20 410583912229872
21 2514779283989460