# A251593 (b-file synthesized from sequence entry)
0 1
1 0
2 1
3 1
4 6
5 21
6 120
7 702
8 4851
9 36549
10 302031
11 2687435
12 25561745
13 257747493
14 2738202129
15 30482602101
16 353982846285
17 427126636983
18 53371267903029
19 688581489582657
20 9149097089801836
21 124906922737719625
22 1748648316615176130