# A075225 (b-file synthesized from sequence entry)
0 1
1 4
2 4
3 16
4 84
5 496
6 3120
7 20416
8 137300
9 942384
10 6572336
11 46432960
12 331580272
13 2389352256
14 17351364160
15 126851634432
16 932823545428
17 6895102385072
18 51199649648048
19 381738099675840
20 2856639909232112
21 21447771308542784