# A138295 (b-file synthesized from sequence entry)
0 1
1 2
2 6
3 27
4 138
5 789
6 4878
7 32114
8 222690
9 1614412
10 12169408
11 94991253
12 765378476
13 6349688936
14 54128566708
15 473335781532
16 4240051400948
17 38861053427316
18 364044827292880
19 3482608706581056
20 33995600317705974
21 338380105093268866