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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 8 |
| 4 | 24 |
| 5 | 72 |
| 6 | 240 |
| 7 | 960 |
| 8 | 2880 |
| 9 | 15360 |
| 10 | 69120 |
| 11 | 165888 |
| 12 | 912384 |
| 13 | 3041280 |
| 14 | 9123840 |
| 15 | 34062336 |
| 16 | 127733760 |
| 17 | 479001600 |
| 18 | 1596672000 |
| 19 | 6386688000 |
| 20 | 22992076800 |
| 21 | 102187008000 |
| 22 | 429185433600 |
| 23 | 1755758592000 |
| 24 | 6730407936000 |
| 25 | 28267713331200 |
[1,2,8,24,72,240,960,2880,15360,69120,165888, 912384,3041280,9123840,34062336,127733760, 479001600,1596672000,6386688000,22992076800, 102187008000,429185433600,1755758592000, 6730407936000,28267713331200] |