# A109572 (b-file synthesized from sequence entry)
0 0
1 1
2 2
3 6
4 32
5 200
6 1536
7 13664
8 139264
9 1595520
10 20316160
11 284534272
12 4347396096
13 71958415360
14 1282685272064
15 24497477345280
16 499058556796928
17 10802158189445120
18 247567232110952448
19 5989035387568652288