# A002676 (b-file synthesized from sequence entry)
2 1
3 6
4 80
5 30240
6 1814400
7 2661120
8 871782912000
9 3138418483200
10 84687482880000
11 170303140572364800
12 1124000727777607680000
13 724146127139635200000
14 12703681025488077520896000000
15 76222086152928465125376000000
16 1531041037877004667453440000000