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| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 3 |
| 3 | 3 |
| 4 | 9 |
| 5 | 19 |
| 6 | 59 |
| 7 | 129 |
| 8 | 355 |
| 9 | 891 |
| 10 | 2317 |
| 11 | 6019 |
| 12 | 15543 |
| 13 | 40557 |
| 14 | 105639 |
| 15 | 274475 |
| 16 | 716909 |
| 17 | 1868955 |
| 18 | 4870915 |
| 19 | 12717105 |
| 20 | 33177547 |
| 21 | 86555071 |
| 22 | 225940757 |
| 23 | 589641087 |
| 24 | 1538803595 |
| 25 | 4016626149 |
| 26 | 10483511171 |
| 27 | 27362265959 |
| 28 | 71420814253 |
| 29 | 186418208451 |
[3,3,3,9,19,59,129,355,891,2317,6019,15543,40557, 105639,274475,716909,1868955,4870915,12717105, 33177547,86555071,225940757,589641087,1538803595, 4016626149,10483511171,27362265959,71420814253, 186418208451] |