# A047018 (b-file synthesized from sequence entry)
0 1
1 4
2 15
3 55
4 203
5 756
6 2835
7 10698
8 40590
9 154711
10 591998
11 2272920
12 8752198
13 33787677
14 130729863
15 506821408
16 1968360249
17 7656736914
18 29826609906
19 116339203127
20 454317156153
21 1776063279485
22 6950000821250
23 27220990233570