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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 14 |
| 3 | 80 |
| 4 | 509 |
| 5 | 3459 |
| 6 | 24579 |
| 7 | 180389 |
| 8 | 1356743 |
| 9 | 10402493 |
| 10 | 81004516 |
| 11 | 638886082 |
| 12 | 5093081983 |
| 13 | 40971735401 |
| 14 | 332187974718 |
| 15 | 2711668091448 |
| 16 | 22267979870143 |
| 17 | 183830653156341 |
| 18 | 1524747465249750 |
| 19 | 12700172705956876 |
| 20 | 106187411693668179 |
[1,3,14,80,509,3459,24579,180389,1356743,10402493, 81004516,638886082,5093081983,40971735401, 332187974718,2711668091448,22267979870143, 183830653156341,1524747465249750, 12700172705956876,106187411693668179] |