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| n | a(n) |
|---|---|
| 0 | 3 |
| 1 | 9 |
| 2 | 27 |
| 3 | 69 |
| 4 | 171 |
| 5 | 405 |
| 6 | 939 |
| 7 | 2133 |
| 8 | 4779 |
| 9 | 10581 |
| 10 | 23211 |
| 11 | 50517 |
| 12 | 109227 |
| 13 | 234837 |
| 14 | 502443 |
| 15 | 1070421 |
| 16 | 2271915 |
| 17 | 4805973 |
| 18 | 10136235 |
| 19 | 21321045 |
| 20 | 44739243 |
| 21 | 93672789 |
| 22 | 195734187 |
| 23 | 408245589 |
| 24 | 850045611 |
| 25 | 1767200085 |
| 26 | 3668617899 |
| 27 | 7605671253 |
| 28 | 15748213419 |
| 29 | 32570168661 |
| 30 | 67287820971 |
[3,9,27,69,171,405,939,2133,4779,10581,23211, 50517,109227,234837,502443,1070421,2271915, 4805973,10136235,21321045,44739243,93672789, 195734187,408245589,850045611,1767200085, 3668617899,7605671253,15748213419,32570168661, 67287820971] |