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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 1 |
| 4 | 8 |
| 5 | 20 |
| 6 | 16 |
| 7 | 280 |
| 8 | 4480 |
| 9 | 64 |
| 10 | 44800 |
| 11 | 49280 |
| 12 | 1971200 |
| 13 | 1830400 |
| 14 | 14350336 |
| 15 | 896896000 |
| 16 | 74547200 |
| 17 | 243955712000 |
| 18 | 6823936000 |
| 19 | 109062553600 |
| 20 | 52973240320000 |
| 21 | 51913775513600 |
| 22 | 3359126650880000 |
| 23 | 93815608606720000 |
| 24 | 2101469632790528000 |
[1,1,2,1,8,20,16,280,4480,64,44800,49280,1971200, 1830400,14350336,896896000,74547200,243955712000, 6823936000,109062553600,52973240320000, 51913775513600,3359126650880000,93815608606720000, 2101469632790528000] |