# A018934 (b-file synthesized from sequence entry)
0 0
1 0
2 0
3 2
4 8
5 42
6 256
7 1810
8 14568
9 131642
10 1320128
11 14551074
12 174879880
13 2276108362
14 31894886208
15 478775722802
16 7664993150696
17 130369025763930
18 2347604596782208
19 44619881467365442
20 892659329531868168
21 18750556523491299434
22 412601744979927877760
23 9491630163800726992722