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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 13 |
| 2 | 86 |
| 3 | 603 |
| 4 | 4620 |
| 5 | 37299 |
| 6 | 1533327 |
| 7 | 22568442 |
| 8 | 23574105 |
| 9 | 210014510 |
| 10 | 1893613727 |
| 11 | 17241353173 |
| 12 | 493582559244 |
[1,13,86,603,4620,37299,1533327,22568442,23574105, 210014510,1893613727,17241353173,493582559244] |