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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 21 |
| 3 | 230 |
| 4 | 2586 |
| 5 | 29310 |
| 6 | 331589 |
| 7 | 3751888 |
| 8 | 42452438 |
| 9 | 480346122 |
| 10 | 5435081884 |
| 11 | 61497557384 |
| 12 | 695840407309 |
| 13 | 7873383816355 |
| 14 | 89086767652576 |
| 15 | 1008010323915227 |
| 16 | 11405563810447637 |
| 17 | 129053128472692922 |
| 18 | 1460226802057078840 |
[1,21,230,2586,29310,331589,3751888,42452438, 480346122,5435081884,61497557384,695840407309, 7873383816355,89086767652576,1008010323915227, 11405563810447637,129053128472692922, 1460226802057078840] |