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| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 6 |
| 3 | 15 |
| 4 | 34 |
| 5 | 86 |
| 6 | 216 |
| 7 | 548 |
| 8 | 1411 |
| 9 | 3677 |
| 10 | 9620 |
| 11 | 25295 |
| 12 | 66735 |
| 13 | 176535 |
| 14 | 467996 |
| 15 | 1242482 |
| 16 | 3302288 |
| 17 | 8784052 |
| 18 | 23380492 |
| 19 | 62260290 |
| 20 | 165852146 |
| 21 | 441922281 |
| 22 | 1177759338 |
| 23 | 3139292092 |
| 24 | 8368647137 |
| 25 | 22310795823 |
| 26 | 59484268376 |
[3,6,15,34,86,216,548,1411,3677,9620,25295,66735, 176535,467996,1242482,3302288,8784052,23380492, 62260290,165852146,441922281,1177759338, 3139292092,8368647137,22310795823,59484268376] |