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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 18 |
| 5 | 48 |
| 6 | 480 |
| 7 | 1440 |
| 8 | 20160 |
| 9 | 120960 |
| 10 | 1451520 |
| 11 | 7257600 |
| 12 | 239500800 |
| 13 | 958003200 |
| 14 | 24908083200 |
| 15 | 348713164800 |
| 16 | 6538371840000 |
| 17 | 41845579776000 |
| 18 | 2134124568576000 |
| 19 | 12804747411456000 |
| 20 | 729870602452992000 |
| 21 | 9731608032706560000 |
| 22 | 204363768686837760000 |
| 23 | 2248001455555215360000 |
| 24 | 206816133911079813120000 |
[1,2,4,18,48,480,1440,20160,120960,1451520, 7257600,239500800,958003200,24908083200, 348713164800,6538371840000,41845579776000, 2134124568576000,12804747411456000, 729870602452992000,9731608032706560000, 204363768686837760000,2248001455555215360000, 206816133911079813120000] |