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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 24 |
| 4 | 1155 |
| 5 | 337600 |
| 6 | 477339104 |
| 7 | 2872202028544 |
| 8 | 72057595967327280 |
| 9 | 7462505059899321934848 |
| 10 | 3169126500571074529208754688 |
| 11 | 5492677668532710795071525279789056 |
| 12 | 38716571525226776289479030777851808143360 |
| 13 | 1106936151351216411420552029913564174524281470976 |
[1,4,24,1155,337600,477339104,2872202028544, 72057595967327280,7462505059899321934848, 3169126500571074529208754688, 5492677668532710795071525279789056, 38716571525226776289479030777851808143360, 1106936151351216411420552029913564174524281470976] |