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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 12 |
| 4 | 3 |
| 5 | 45 |
| 6 | 18 |
| 7 | 560 |
| 8 | 2520 |
| 9 | 8400 |
| 10 | 225 |
| 11 | 207900 |
| 12 | 207900 |
| 13 | 840840 |
| 14 | 191100 |
| 15 | 7761600 |
| 16 | 50450400 |
| 17 | 15437822400 |
| 18 | 14034384 |
| 19 | 214885440 |
| 20 | 29331862560 |
| 21 | 645300976320 |
| 22 | 517068090 |
| 23 | 742096122768 |
| 24 | 463810076730 |
| 25 | 4466319257400 |
| 26 | 492206612040 |
| 27 | 68908925685600 |
| 28 | 11484820947600 |
[1,1,12,3,45,18,560,2520,8400,225,207900,207900, 840840,191100,7761600,50450400,15437822400, 14034384,214885440,29331862560,645300976320, 517068090,742096122768,463810076730,4466319257400, 492206612040,68908925685600,11484820947600] |