# A138782 (b-file synthesized from sequence entry)
1 1
2 10
3 72
4 528
5 4200
6 36720
7 352800
8 3709440
9 42456960
10 526176000
11 7025356800
12 100590336000
13 1538074137600
14 25020169574400
15 431532541440000
16 7866968997888000
17 151167156940800000
18 3053932257632256000