# A002912 (b-file synthesized from sequence entry)
1 0
2 0
3 1
4 6
5 27
6 122
7 516
8 2148
9 8792
10 35622
11 143079
12 570830
13 2264649
14 8942436
15 35169616
16 137839308
17 538594704
18 2098892928
19 8159937669
20 31656305550
21 122575164923
22 473797120338
23 1828512928200
24 7046581314292
25 27119735418924
26 104247226432566
27 400272672674603