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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 8 |
| 5 | 23 |
| 6 | 71 |
| 7 | 226 |
| 8 | 743 |
| 9 | 2500 |
| 10 | 8570 |
| 11 | 29828 |
| 12 | 105116 |
| 13 | 374308 |
[1,1,1,3,8,23,71,226,743,2500,8570,29828,105116, 374308] |