# A108552 (b-file synthesized from sequence entry)
1 1
2 1
3 8
4 180
5 1120
6 8064
7 604800
8 68428800
9 830269440
10 10897286400
11 2324754432000
12 640237370572800
13 11585247657984000
14 221172909834240000
15 93666727314800640000
16 2068161339110798131200
17 47726800133326110720000
18 1148978521728221184000000
19 28806532937614688256000000