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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 36 |
| 5 | 180 |
| 6 | 1080 |
| 7 | 7560 |
| 8 | 60480 |
| 9 | 544320 |
| 10 | 5443200 |
| 11 | 59875200 |
| 12 | 718502400 |
| 13 | 9340531200 |
| 14 | 130767436800 |
| 15 | 1961511552000 |
| 16 | 31384184832000 |
| 17 | 533531142144000 |
| 18 | 9603560558592000 |
| 19 | 182467650613248000 |
| 20 | 3649353012264960000 |
| 21 | 76636413257564160000 |
| 22 | 1686001091666411520000 |
| 23 | 38778025108327464960000 |
[1,3,9,36,180,1080,7560,60480,544320,5443200, 59875200,718502400,9340531200,130767436800, 1961511552000,31384184832000,533531142144000, 9603560558592000,182467650613248000, 3649353012264960000,76636413257564160000, 1686001091666411520000,38778025108327464960000] |