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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 4 |
| 3 | 6 |
| 4 | 32 |
| 5 | 60 |
| 6 | 384 |
| 7 | 840 |
| 8 | 6144 |
| 9 | 15120 |
| 10 | 122880 |
| 11 | 332640 |
| 12 | 2949120 |
| 13 | 8648640 |
| 14 | 82575360 |
| 15 | 259459200 |
| 16 | 2642411520 |
| 17 | 8821612800 |
| 18 | 95126814720 |
| 19 | 335221286400 |
| 20 | 3805072588800 |
| 21 | 14079294028800 |
| 22 | 167423193907200 |
| 23 | 647647525324800 |
[1,1,4,6,32,60,384,840,6144,15120,122880,332640, 2949120,8648640,82575360,259459200,2642411520, 8821612800,95126814720,335221286400,3805072588800, 14079294028800,167423193907200,647647525324800] |