# A073994 (b-file synthesized from sequence entry)
1 0
2 0
3 6
4 48
5 300
6 1800
7 9072
8 44928
9 252720
10 1555200
11 9722592
12 60217344
13 367960320
14 2213827200
15 13180786560
16 78399995904
17 468419708160
18 2810518248960
19 16894457846784
20 101554796888064
21 609923828966400
22 3659666929459200
23 21947538146863104
24 131620960833896448