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| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 6 |
| 3 | 14 |
| 4 | 36 |
| 5 | 99 |
| 6 | 281 |
| 7 | 816 |
| 8 | 2415 |
| 9 | 7260 |
| 10 | 22074 |
| 11 | 67743 |
| 12 | 209552 |
| 13 | 652566 |
| 14 | 2043672 |
| 15 | 6431715 |
| 16 | 20328504 |
| 17 | 64494678 |
| 18 | 205303537 |
| 19 | 655493697 |
| 20 | 2098500135 |
| 21 | 6734498816 |
| 22 | 21660087087 |
| 23 | 69805491342 |
[3,6,14,36,99,281,816,2415,7260,22074,67743, 209552,652566,2043672,6431715,20328504,64494678, 205303537,655493697,2098500135,6734498816, 21660087087,69805491342] |