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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 17 |
| 5 | 73 |
| 6 | 397 |
| 7 | 2623 |
| 8 | 20414 |
| 9 | 181607 |
| 10 | 1809104 |
| 11 | 19886032 |
| 12 | 238723606 |
[1,1,2,5,17,73,397,2623,20414,181607,1809104, 19886032,238723606] |