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| n | a(n) |
|---|---|
| 0 | -1 |
| 1 | 7 |
| 2 | 2911 |
| 3 | 40391 |
| 4 | 242047 |
| 5 | 950599 |
| 6 | 2883167 |
| 7 | 7338631 |
| 8 | 16451071 |
| 9 | 33489287 |
| 10 | 63202399 |
| 11 | 112211527 |
| 12 | 189447551 |
| 13 | 306634951 |
| 14 | 478821727 |
| 15 | 724955399 |
| 16 | 1068505087 |
| 17 | 1538129671 |
| 18 | 2168392031 |
| 19 | 3000519367 |
| 20 | 4083209599 |
| 21 | 5473483847 |
| 22 | 7237584991 |
| 23 | 9451922311 |
| 24 | 12204062207 |
| 25 | 15593764999 |
[-1,7,2911,40391,242047,950599,2883167,7338631, 16451071,33489287,63202399,112211527,189447551, 306634951,478821727,724955399,1068505087, 1538129671,2168392031,3000519367,4083209599, 5473483847,7237584991,9451922311,12204062207, 15593764999] |