# A007223 (b-file synthesized from sequence entry)
2 1
3 2
4 8
5 24
6 85
7 286
8 1008
9 3536
10 12618
11 45220
12 163504
13 594320
14 2173197
15 7983990
16 29465440
17 109174560
18 405995326
19 1514797020
20 5669021488
21 21275014800
22 80047272578
23 301892460012
24 1141069157408
25 4321730134624
26 16399422757300