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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 6 |
| 2 | 145 |
| 3 | 876 |
| 4 | 21169 |
| 5 | 127890 |
| 6 | 3090529 |
| 7 | 18671064 |
| 8 | 451196065 |
| 9 | 2725847454 |
| 10 | 65871534961 |
| 11 | 397955057220 |
| 12 | 9616792908241 |
| 13 | 58098712506666 |
| 14 | 1403985893068225 |
| 15 | 8482014070916016 |
| 16 | 204972323595052609 |
| 17 | 1238315955641231670 |
| 18 | 29924555258984612689 |
| 19 | 180785647509548907804 |
[1,6,145,876,21169,127890,3090529,18671064, 451196065,2725847454,65871534961,397955057220, 9616792908241,58098712506666,1403985893068225, 8482014070916016,204972323595052609, 1238315955641231670,29924555258984612689, 180785647509548907804] |