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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 17 |
| 6 | 82 |
| 7 | 536 |
| 8 | 5606 |
| 9 | 95915 |
| 10 | 2784072 |
| 11 | 135885572 |
| 12 | 10977061102 |
| 13 | 1448150962596 |
[1,1,2,5,17,82,536,5606,95915,2784072,135885572, 10977061102,1448150962596] |