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A120081 as a simple table

na(n)
01
18
220
31
41680
51
690720
71
84435200
91
10207567360
111
126538371840000
131
14423437414400
151
1667580611338240000
171
1835763659520196608000
191
206155242080686899200000
211
22117509166994931712000000
231

[1,8,20,1,1680,1,90720,1,4435200,1,207567360,1,
 6538371840000,1,423437414400,1,67580611338240000,
 1,35763659520196608000,1,6155242080686899200000,1,
 117509166994931712000000,1]