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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 13 |
| 3 | 89 |
| 4 | 691 |
| 5 | 5720 |
| 6 | 49555 |
| 7 | 443630 |
| 8 | 4071595 |
| 9 | 38105342 |
| 10 | 362271823 |
| 11 | 3488988101 |
| 12 | 33967656469 |
| 13 | 333752559392 |
| 14 | 3305347855573 |
| 15 | 32960499084305 |
| 16 | 330664662067795 |
| 17 | 3335002912108670 |
| 18 | 33796042027030855 |
| 19 | 343940115478559699 |
| 20 | 3513702627928096681 |
| 21 | 36021007341027948032 |
[1,2,13,89,691,5720,49555,443630,4071595,38105342, 362271823,3488988101,33967656469,333752559392, 3305347855573,32960499084305,330664662067795, 3335002912108670,33796042027030855, 343940115478559699,3513702627928096681, 36021007341027948032] |