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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 5 |
| 3 | 13 |
| 4 | 36 |
| 5 | 110 |
| 6 | 366 |
| 7 | 1688 |
| 8 | 5312 |
| 9 | 24921 |
| 10 | 101495 |
| 11 | 417118 |
| 12 | 1673507 |
| 13 | 6081357 |
| 14 | 22843019 |
| 15 | 72935735 |
| 16 | 238112928 |
| 17 | 734665224 |
| 18 | 2185350505 |
[2,5,13,36,110,366,1688,5312,24921,101495,417118, 1673507,6081357,22843019,72935735,238112928, 734665224,2185350505] |