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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 40 |
| 2 | 2016 |
| 3 | 135680 |
| 4 | 11977856 |
| 5 | 1351633920 |
| 6 | 190346960896 |
| 7 | 32769353973760 |
| 8 | 6776471542235136 |
| 9 | 1658320063181619200 |
| 10 | 474140484461265944576 |
| 11 | 156647023437347542794240 |
| 12 | 59229231136268698009993216 |
[1,40,2016,135680,11977856,1351633920, 190346960896,32769353973760,6776471542235136, 1658320063181619200,474140484461265944576, 156647023437347542794240, 59229231136268698009993216] |