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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 31 |
| 3 | 342 |
| 4 | 2910 |
| 5 | 25273 |
| 6 | 251972 |
| 7 | 2579814 |
| 8 | 24550379 |
| 9 | 230860577 |
| 10 | 2228487362 |
| 11 | 21701017288 |
| 12 | 209232791158 |
| 13 | 2007839656980 |
| 14 | 19335726884633 |
| 15 | 186641182758431 |
| 16 | 1799468819059552 |
| 17 | 17330304902080402 |
| 18 | 166963816148786657 |
[1,31,342,2910,25273,251972,2579814,24550379, 230860577,2228487362,21701017288,209232791158, 2007839656980,19335726884633,186641182758431, 1799468819059552,17330304902080402, 166963816148786657] |