# A002863 (b-file synthesized from sequence entry)
1 0
2 0
3 1
4 1
5 2
6 3
7 7
8 21
9 49
10 165
11 552
12 2176
13 9988
14 46972
15 253293
16 1388705
17 8053393
18 48266466
19 294130458