# A006648 (b-file synthesized from sequence entry)
2 1
3 1
4 2
5 4
6 9
7 20
8 50
9 124
10 332
11 895
12 2513
13 7172
14 20994
15 62366
16 188696
17 578717
18 1799999
19 5666257
20 18047319
21 58097540
22 188953756
23 620493315
24 2056582095
25 6877206111
26 23195975865
27 78891742748
28 270505303760
29 934890953041
30 3256230606767