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A199495 as a simple table

na(n)
00
11
20
32
44
536
6144
71440
88640
9100800
10806400
1110886400
12108864000
131676505600
1420118067200
15348713164800
164881984307200
1794152554496000
181506440871936000
1932011868528640000
20576213633515520000
2113380961044971520000
22267619220899430400000

[0,1,0,2,4,36,144,1440,8640,100800,806400,
 10886400,108864000,1676505600,20118067200,
 348713164800,4881984307200,94152554496000,
 1506440871936000,32011868528640000,
 576213633515520000,13380961044971520000,
 267619220899430400000]