# A093571 (b-file synthesized from sequence entry)
1 3
2 15
3 120
4 1320
5 2640
6 50160
7 50160
8 451440
9 902880
10 11737440
11 82162080
12 575134560
13 575134560
14 575134560
15 17829171360
16 410070941280
17 410070941280
18 32395604361120
19 1393010987528160
20 1393010987528160
21 65471516413823520