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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 3 |
| 4 | 5 |
| 5 | 8 |
| 6 | 15 |
| 7 | 27 |
| 8 | 57 |
| 9 | 142 |
| 10 | 381 |
| 11 | 1110 |
| 12 | 3484 |
| 13 | 11678 |
| 14 | 41566 |
| 15 | 156319 |
| 16 | 618829 |
| 17 | 2570651 |
| 18 | 11174315 |
| 19 | 50704149 |
| 20 | 239641306 |
| 21 | 1177394450 |
| 22 | 6002778135 |
| 23 | 31706648191 |
| 24 | 173250478087 |
| 25 | 977993291266 |
| 26 | 5696294311736 |
| 27 | 34193455142322 |
| 28 | 211311452026745 |
[1,2,3,5,8,15,27,57,142,381,1110,3484,11678,41566, 156319,618829,2570651,11174315,50704149,239641306, 1177394450,6002778135,31706648191,173250478087, 977993291266,5696294311736,34193455142322, 211311452026745] |