# A121643 (b-file synthesized from sequence entry)
0 1
1 1
2 1
3 2
4 9
5 28
6 66
7 153
8 433
9 1352
10 4104
11 12188
12 37506
13 124155
14 422307
15 1437135
16 5058945
17 18255295
18 65336580
19 232233723
20 832793160
21 3003712770
22 10788778026
23 38582183151
24 137946936834
25 493981065171
26 1770660835057
27 6347845365236