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A121635 as a simple table

na(n)
11
21
32
48
542
6264
71920
815840
9146160
101491840
1116692480
12203212800
132674425600
1437841126400
15572885913600
169240898867200
17158228598528000
182866422214656000
1954775863926784000
201101208277385216000
2123234214178086912000
22513342323725271040000

[1,1,2,8,42,264,1920,15840,146160,1491840,
 16692480,203212800,2674425600,37841126400,
 572885913600,9240898867200,158228598528000,
 2866422214656000,54775863926784000,
 1101208277385216000,23234214178086912000,
 513342323725271040000]