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| n | a(n) |
|---|---|
| 1 | 6 |
| 2 | 420 |
| 3 | 72072 |
| 4 | 760760 |
| 5 | 1266697832400 |
| 6 | 783333734619744 |
| 7 | 3002950101013562700 |
| 8 | 1253414030788528596187200 |
| 9 | 27809824888100301666382826331840 |
| 10 | 118802724769051077369996224554510800 |
| 11 | 2005396188718644499811084404372455793370133120 |
[6,420,72072,760760,1266697832400,783333734619744, 3002950101013562700,1253414030788528596187200, 27809824888100301666382826331840, 118802724769051077369996224554510800, 2005396188718644499811084404372455793370133120] |