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A256881 as a simple table

na(n)
11
22
33
412
540
6240
71260
810080
972576
10725760
116652800
1279833600
13889574400
1412454041600
15163459296000
162615348736000
1739520825344000
18711374856192000
1912164510040883200
20243290200817664000
214644631106519040000
22102181884343418880000
232154334728240414720000

[1,2,3,12,40,240,1260,10080,72576,725760,6652800,
 79833600,889574400,12454041600,163459296000,
 2615348736000,39520825344000,711374856192000,
 12164510040883200,243290200817664000,
 4644631106519040000,102181884343418880000,
 2154334728240414720000]