# A069141 (b-file synthesized from sequence entry)
1 2
2 6
3 24
4 30
5 720
6 140
7 40320
8 5670
9 403200
10 399168
11 479001600
12 300300
13 87178291200
14 6671808000
15 92990177280
16 86837751000
17 6402373705728000
18 1158789632000
19 2432902008176640000
20 319318388573184
21 2548754484756480000