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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 17 |
| 5 | 51 |
| 6 | 152 |
| 7 | 456 |
| 8 | 1367 |
| 9 | 4101 |
| 10 | 12302 |
| 11 | 36906 |
| 12 | 110717 |
| 13 | 332151 |
| 14 | 996452 |
| 15 | 2989356 |
| 16 | 8968067 |
| 17 | 26904201 |
| 18 | 80712602 |
| 19 | 242137806 |
| 20 | 726413417 |
| 21 | 2179240251 |
| 22 | 6537720752 |
| 23 | 19613162256 |
| 24 | 58839486767 |
| 25 | 176518460301 |
| 26 | 529555380902 |
| 27 | 1588666142706 |
| 28 | 4765998428117 |
| 29 | 14297995284351 |
[1,2,6,17,51,152,456,1367,4101,12302,36906,110717, 332151,996452,2989356,8968067,26904201,80712602, 242137806,726413417,2179240251,6537720752, 19613162256,58839486767,176518460301,529555380902, 1588666142706,4765998428117,14297995284351] |