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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 2 |
| 3 | 6 |
| 4 | 8 |
| 5 | 120 |
| 6 | 12 |
| 7 | 5040 |
| 8 | 384 |
| 9 | 12960 |
| 10 | 640 |
| 11 | 39916800 |
| 12 | 1152 |
| 13 | 6227020800 |
| 14 | 80640 |
| 15 | 5443200 |
| 16 | 10321920 |
| 17 | 355687428096000 |
| 18 | 290304 |
| 19 | 121645100408832000 |
| 20 | 38707200 |
| 21 | 384758035200 |
| 22 | 6812467200 |
| 23 | 25852016738884976640000 |
| 24 | 139345920 |
[2,2,6,8,120,12,5040,384,12960,640,39916800,1152, 6227020800,80640,5443200,10321920,355687428096000, 290304,121645100408832000,38707200,384758035200, 6812467200,25852016738884976640000,139345920] |