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| n | a(n) |
|---|---|
| 2 | 6 |
| 3 | 20 |
| 4 | 57960 |
| 5 | 3145940416080 |
| 6 | 5765760 |
| 7 | 288680192354725622464710969631440008928 |
| 8 | 20484953806009937929429725901717124022833778640 |
| 9 | 59553628273094395440 |
| 10 | 102119994931499628863688098762720537989600 |
[6,20,57960,3145940416080,5765760, 288680192354725622464710969631440008928, 20484953806009937929429725901717124022833778640, 59553628273094395440, 102119994931499628863688098762720537989600] |