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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 29 |
| 5 | 99 |
| 6 | 360 |
| 7 | 1357 |
| 8 | 5203 |
| 9 | 20370 |
| 10 | 81126 |
| 11 | 327936 |
| 12 | 1341708 |
| 13 | 5538553 |
| 14 | 23057491 |
| 15 | 96745210 |
| 16 | 408716932 |
| 17 | 1736757396 |
| 18 | 7418365253 |
| 19 | 31835377665 |
| 20 | 137216306947 |
| 21 | 593770969859 |
| 22 | 2578522060500 |
| 23 | 11233959191344 |
| 24 | 49090715171230 |
| 25 | 215118601209475 |
| 26 | 945106337138974 |
| 27 | 4162197021625413 |
| 28 | 18370926413447123 |
[1,1,3,9,29,99,360,1357,5203,20370,81126,327936, 1341708,5538553,23057491,96745210,408716932, 1736757396,7418365253,31835377665,137216306947, 593770969859,2578522060500,11233959191344, 49090715171230,215118601209475,945106337138974, 4162197021625413,18370926413447123] |