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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 12 |
| 3 | 120 |
| 4 | 1680 |
| 5 | 10080 |
| 6 | 221760 |
| 7 | 2217600 |
| 8 | 34594560 |
| 9 | 345945600 |
| 10 | 11762150400 |
| 11 | 29059430400 |
| 12 | 988020633600 |
| 13 | 21736453939200 |
| 14 | 225268704460800 |
| 15 | 5999261287219200 |
| 16 | 642466345122201600 |
| 17 | 1367831573485977600 |
[2,12,120,1680,10080,221760,2217600,34594560, 345945600,11762150400,29059430400,988020633600, 21736453939200,225268704460800,5999261287219200, 642466345122201600,1367831573485977600] |