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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 8 |
| 4 | 25 |
| 5 | 89 |
| 6 | 349 |
| 7 | 1496 |
| 8 | 6962 |
| 9 | 34861 |
| 10 | 186678 |
| 11 | 1063591 |
| 12 | 6418167 |
| 13 | 40860485 |
| 14 | 273513831 |
| 15 | 1919284246 |
| 16 | 14080876273 |
| 17 | 107750778177 |
| 18 | 858195666410 |
| 19 | 7100543662976 |
| 20 | 60922480229704 |
| 21 | 541193416875432 |
| 22 | 4970306167860426 |
[1,1,3,8,25,89,349,1496,6962,34861,186678,1063591, 6418167,40860485,273513831,1919284246,14080876273, 107750778177,858195666410,7100543662976, 60922480229704,541193416875432,4970306167860426] |