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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 9 |
| 3 | 33 |
| 4 | 129 |
| 5 | 511 |
| 6 | 2110 |
| 7 | 8883 |
| 8 | 37770 |
| 9 | 163078 |
| 10 | 711157 |
| 11 | 3122349 |
| 12 | 13813470 |
| 13 | 61489000 |
| 14 | 274994926 |
| 15 | 1235534550 |
| 16 | 5574180288 |
| 17 | 25233308678 |
| 18 | 114589332333 |
| 19 | 521906125367 |
| 20 | 2383113544526 |
| 21 | 10907286930454 |
| 22 | 50031574548984 |
| 23 | 229948117747006 |
| 24 | 1058783283652308 |
| 25 | 4883463242267293 |
| 26 | 22559695965552386 |
| 27 | 104369418822478204 |
[1,3,9,33,129,511,2110,8883,37770,163078,711157, 3122349,13813470,61489000,274994926,1235534550, 5574180288,25233308678,114589332333,521906125367, 2383113544526,10907286930454,50031574548984, 229948117747006,1058783283652308,4883463242267293, 22559695965552386,104369418822478204] |