# A013416 (b-file synthesized from sequence entry)
0 1
1 0
2 0
3 2
4 0
5 0
6 40
7 450
8 0
9 2240
10 108000
11 1786050
12 246400
13 30888000
14 1647734400
15 36567781250
16 11531520000
17 1356752592000
18 85195294912000
19 2380490964101250
20 1210714801920000
21 153377369153840000