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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 12 |
| 5 | 72 |
| 6 | 336 |
| 7 | 1824 |
| 8 | 13152 |
| 9 | 134880 |
| 10 | 649296 |
| 11 | 8572800 |
| 12 | 102194400 |
| 13 | 1033046880 |
| 14 | 12143232960 |
| 15 | 210042192960 |
| 16 | 2372176649280 |
| 17 | 46447968686400 |
| 18 | 648516678024960 |
[1,2,6,12,72,336,1824,13152,134880,649296,8572800, 102194400,1033046880,12143232960,210042192960, 2372176649280,46447968686400,648516678024960] |