# A331505 (b-file synthesized from sequence entry)
1 1
2 1
3 3
4 15
5 45
6 455
7 1330
8 20475
9 58905
10 1221759
11 3478761
12 90858768
13 256851595
14 8093990190
15 22760723700
16 840261910995
17 2353351951665
18 99615373765775
19 278110855548955
20 13278694407181203
21 36976937738226486