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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 6 |
| 2 | 17 |
| 3 | 100 |
| 4 | 1377 |
| 5 | 13682 |
| 6 | 109873 |
| 7 | 806736 |
| 8 | 5732033 |
| 9 | 40294558 |
| 10 | 282375249 |
| 11 | 1977165692 |
| 12 | 13841038369 |
| 13 | 96888639114 |
| 14 | 678222535025 |
| 15 | 4747560750568 |
| 16 | 33232929521025 |
| 17 | 232630512567350 |
| 18 | 1628413596020881 |
| 19 | 11398895182897044 |
[1,6,17,100,1377,13682,109873,806736,5732033, 40294558,282375249,1977165692,13841038369, 96888639114,678222535025,4747560750568, 33232929521025,232630512567350,1628413596020881, 11398895182897044] |