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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 32 |
| 5 | 126 |
| 6 | 564 |
| 7 | 2700 |
| 8 | 13802 |
| 9 | 74422 |
| 10 | 422812 |
| 11 | 2519962 |
| 12 | 15731562 |
| 13 | 102390662 |
| 14 | 692779852 |
| 15 | 4851392308 |
| 16 | 35068814616 |
| 17 | 261013287116 |
| 18 | 1997276928946 |
| 19 | 15689964298430 |
| 20 | 126416353430344 |
| 21 | 1043615269337354 |
| 22 | 8819704403143576 |
| 23 | 76229300376178238 |
| 24 | 673190822341507644 |
[1,1,3,9,32,126,564,2700,13802,74422,422812, 2519962,15731562,102390662,692779852,4851392308, 35068814616,261013287116,1997276928946, 15689964298430,126416353430344,1043615269337354, 8819704403143576,76229300376178238, 673190822341507644] |