# A073976 (b-file synthesized from sequence entry)
1 0
2 2
3 18
4 72
5 300
6 1440
7 7056
8 39312
9 252720
10 1658880
11 10349856
12 62099136
13 367960320
14 2179768320
15 12976433280
16 77787495936
17 468419708160
18 2821539889152
19 16960580969472
20 101753146100736
21 609923828966400
22 3656096522698752
23 21926115464435712
24 131556692786614272