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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 3 |
| 6 | 5 |
| 7 | 15 |
| 8 | 27 |
| 9 | 71 |
| 10 | 187 |
| 11 | 699 |
| 12 | 2485 |
| 13 | 10357 |
| 14 | 44365 |
| 15 | 244417 |
| 16 | 1388829 |
| 17 | 9098951 |
| 18 | 61499491 |
| 19 | 509779147 |
| 20 | 4539566193 |
| 21 | 48133963115 |
| 22 | 521951245563 |
| 23 | 6723339029473 |
| 24 | 91767923636107 |
| 25 | 1516162394272495 |
| 26 | 26177605341894705 |
| 27 | 536020923137750911 |
[1,1,1,1,3,5,15,27,71,187,699,2485,10357,44365, 244417,1388829,9098951,61499491,509779147, 4539566193,48133963115,521951245563,6723339029473, 91767923636107,1516162394272495,26177605341894705, 536020923137750911] |