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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 6 |
| 3 | 40 |
| 4 | 84 |
| 5 | 990 |
| 6 | 936 |
| 7 | 5100 |
| 8 | 8208 |
| 9 | 12420 |
| 10 | 48720 |
| 11 | 37200 |
| 12 | 139860 |
| 13 | 196800 |
| 14 | 216720 |
| 15 | 118440 |
| 16 | 648720 |
| 17 | 2180640 |
| 18 | 1024800 |
| 19 | 1857240 |
| 20 | 2385600 |
| 21 | 2522880 |
| 22 | 4180680 |
| 23 | 3884400 |
| 24 | 9868320 |
| 25 | 17599680 |
| 26 | 21816000 |
| 27 | 16315200 |
| 28 | 18874800 |
| 29 | 51273600 |
| 30 | 34171200 |
| 31 | 48646080 |
| 32 | 120163680 |
| 33 | 110674080 |
[2,6,40,84,990,936,5100,8208,12420,48720,37200, 139860,196800,216720,118440,648720,2180640, 1024800,1857240,2385600,2522880,4180680,3884400, 9868320,17599680,21816000,16315200,18874800, 51273600,34171200,48646080,120163680,110674080] |