# A095823 (b-file synthesized from sequence entry)
1 1
2 4
3 18
4 32
5 600
6 4320
7 11760
8 322560
9 3265920
10 1728000
11 439084800
12 821145600
13 817689600
14 1220496076800
15 19615115520000
16 111588212736000
17 863812325376000
18 115242726703104000
19 15722836107264000
20 3742926166425600000