# A008964 (b-file synthesized from sequence entry)
1 1
2 2
3 6
4 28
5 192
6 1952
7 28800
8 618496
9 19132416
10 853508096
11 54584672256
12 5007197863936
13 656391329021952
14 122997864673574912
15 32863344789678981120
16 12522141669213840867328
17 6792468641646224590503936
18 5245768641385222636392415232