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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 24 |
| 3 | 201 |
| 4 | 1809 |
| 5 | 16893 |
| 6 | 161676 |
| 7 | 1574289 |
| 8 | 15527052 |
| 9 | 154662930 |
| 10 | 1552725504 |
| 11 | 15688410264 |
| 12 | 159355067283 |
| 13 | 1625899880673 |
| 14 | 16652520666414 |
| 15 | 171119405299005 |
| 16 | 1763475423260049 |
| 17 | 18219685282559559 |
| 18 | 188664151412242368 |
| 19 | 1957539823296458841 |
| 20 | 20347733657193596127 |
[1,3,24,201,1809,16893,161676,1574289,15527052, 154662930,1552725504,15688410264,159355067283, 1625899880673,16652520666414,171119405299005, 1763475423260049,18219685282559559, 188664151412242368,1957539823296458841, 20347733657193596127] |