# A007224 (b-file synthesized from sequence entry)
4 2
5 9
6 38
7 143
8 546
9 2066
10 7752
11 29070
12 108968
13 408595
14 1533870
15 5766243
16 21710850
17 81880920
18 309328008
19 1170524970
20 4436618940
21 16842720336
22 64037794548
23 243836217702
24 929759970392
25 3549992610584
26 13571935767600
27 51950354135888