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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 80 |
| 3 | 2160 |
| 4 | 121200 |
| 5 | 6136800 |
| 6 | 356570960 |
| 7 | 21225304800 |
| 8 | 1321586558320 |
| 9 | 84398804078400 |
| 10 | 5518934916677280 |
| 11 | 367489108030524480 |
| 12 | 24852668879410144080 |
| 13 | 1702677155195779963200 |
| 14 | 117960677109321028039200 |
| 15 | 8251450286371615261498560 |
| 16 | 582087494621171173360817520 |
[1,0,80,2160,121200,6136800,356570960,21225304800, 1321586558320,84398804078400,5518934916677280, 367489108030524480,24852668879410144080, 1702677155195779963200,117960677109321028039200, 8251450286371615261498560, 582087494621171173360817520] |