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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 8 |
| 3 | 20 |
| 4 | 49 |
| 5 | 119 |
| 6 | 289 |
| 7 | 707 |
| 8 | 1749 |
| 9 | 4379 |
| 10 | 11092 |
| 11 | 28412 |
| 12 | 73573 |
| 13 | 192535 |
| 14 | 508918 |
| 15 | 1357770 |
| 16 | 3653343 |
| 17 | 9905437 |
| 18 | 27040975 |
| 19 | 74269569 |
| 20 | 205091177 |
| 21 | 569078255 |
| 22 | 1585839062 |
| 23 | 4436191950 |
| 24 | 12452408525 |
| 25 | 35062157207 |
| 26 | 99000292173 |
| 27 | 280242836387 |
| 28 | 795124827781 |
| 29 | 2260758570327 |
[1,3,8,20,49,119,289,707,1749,4379,11092,28412, 73573,192535,508918,1357770,3653343,9905437, 27040975,74269569,205091177,569078255,1585839062, 4436191950,12452408525,35062157207,99000292173, 280242836387,795124827781,2260758570327] |