# A138294 (b-file synthesized from sequence entry)
0 1
1 1
2 4
3 16
4 78
5 420
6 2454
7 15297
8 100660
9 694022
10 4986128
11 37171749
12 286619290
13 2279866324
14 18668221560
15 157080129914
16 1356186583276
17 11999018622158
18 108672944038356
19 1006528378511868
20 9525454067974148
21 92037443236217412