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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 15 |
| 5 | 84 |
| 6 | 55 |
| 7 | 100 |
| 8 | 770 |
| 9 | 1680 |
| 10 | 1323 |
| 11 | 141120 |
| 12 | 8470 |
| 13 | 27720 |
| 14 | 3474900 |
| 15 | 4228224 |
| 16 | 3468465 |
| 17 | 19459440 |
| 18 | 131030900 |
| 19 | 109156320 |
| 20 | 1042578108 |
| 21 | 8779605120 |
| 22 | 1514663280 |
| 23 | 41736380400 |
| 24 | 175685635125 |
| 25 | 24960905112 |
| 26 | 1254125149200 |
| 27 | 4476730258000 |
| 28 | 10664476594200 |
| 29 | 73326164511600 |
[1,2,6,15,84,55,100,770,1680,1323,141120,8470, 27720,3474900,4228224,3468465,19459440,131030900, 109156320,1042578108,8779605120,1514663280, 41736380400,175685635125,24960905112, 1254125149200,4476730258000,10664476594200, 73326164511600] |