# A177138 (b-file synthesized from sequence entry)
1 1
2 3
3 12
4 60
5 360
6 2520
7 20160
8 19958400
9 239500800
10 3113510400
11 43589145600
12 177843714048000
13 3201186852864000
14 60822550204416000
15 1216451004088320000
16 12926008369442488320000
17 310224200866619719680000
18 4420880996869850977271808000000