# A001572 (b-file synthesized from sequence entry)
0 1
1 1
2 1
3 1
4 3
5 5
6 17
7 41
8 127
9 365
10 1119
11 3413
12 10685
13 33561
14 106827
15 342129
16 1104347
17 3584649
18 11701369
19 38374065
20 126395259
21 417908329
22 1386618307
23 4615388353
24 15407188529
25 51569669429
26 173033992311
27 581905285089
28 1961034571967