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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 31 |
| 5 | 109 |
| 6 | 397 |
| 7 | 1469 |
| 8 | 5527 |
| 9 | 21011 |
| 10 | 80569 |
| 11 | 311003 |
| 12 | 1207035 |
| 13 | 4704737 |
| 14 | 18403149 |
| 15 | 72198531 |
| 16 | 283942611 |
| 17 | 1118999005 |
| 18 | 4417672911 |
| 19 | 17466703087 |
| 20 | 69149566107 |
| 21 | 274065214899 |
| 22 | 1087279220395 |
| 23 | 4317148394761 |
| 24 | 17154423083379 |
| 25 | 68208723922417 |
| 26 | 271365767997697 |
| 27 | 1080171683737141 |
| 28 | 4301583514903391 |
[1,1,3,9,31,109,397,1469,5527,21011,80569,311003, 1207035,4704737,18403149,72198531,283942611, 1118999005,4417672911,17466703087,69149566107, 274065214899,1087279220395,4317148394761, 17154423083379,68208723922417,271365767997697, 1080171683737141,4301583514903391] |