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| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 9 |
| 3 | 24 |
| 4 | 63 |
| 5 | 159 |
| 6 | 394 |
| 7 | 957 |
| 8 | 2292 |
| 9 | 5419 |
| 10 | 12678 |
| 11 | 29385 |
| 12 | 67560 |
| 13 | 154215 |
| 14 | 349770 |
| 15 | 788741 |
| 16 | 1769388 |
| 17 | 3950499 |
| 18 | 8782094 |
| 19 | 19445313 |
| 20 | 42898032 |
| 21 | 94315743 |
| 22 | 206709714 |
| 23 | 451711869 |
| 24 | 984397108 |
| 25 | 2139750939 |
| 26 | 4639901334 |
| 27 | 10038505657 |
| 28 | 21672089592 |
| 29 | 46693408599 |
[3,9,24,63,159,394,957,2292,5419,12678,29385, 67560,154215,349770,788741,1769388,3950499, 8782094,19445313,42898032,94315743,206709714, 451711869,984397108,2139750939,4639901334, 10038505657,21672089592,46693408599] |