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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 1 |
| 6 | 1 |
| 7 | 1 |
| 8 | 3 |
| 9 | 5 |
| 10 | 15 |
| 11 | 25 |
| 12 | 43 |
| 13 | 113 |
| 14 | 451 |
| 15 | 1305 |
| 16 | 6863 |
| 17 | 22081 |
| 18 | 100557 |
| 19 | 420517 |
| 20 | 2802713 |
| 21 | 14484461 |
| 22 | 126443483 |
[1,1,1,1,1,1,1,3,5,15,25,43,113,451,1305,6863, 22081,100557,420517,2802713,14484461,126443483] |