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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 9 |
| 6 | 25 |
| 7 | 65 |
| 8 | 305 |
| 9 | 2297 |
| 10 | 32289 |
| 11 | 404565 |
| 12 | 5435093 |
| 13 | 101023199 |
| 14 | 2823418681 |
| 15 | 117113399963 |
[1,1,1,1,9,25,65,305,2297,32289,404565,5435093, 101023199,2823418681,117113399963] |