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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 28 |
| 2 | 497 |
| 3 | 7160 |
| 4 | 91581 |
| 5 | 1086708 |
| 6 | 12265177 |
| 7 | 133727440 |
| 8 | 1422928661 |
| 9 | 14879566988 |
| 10 | 153661601457 |
| 11 | 1572610177320 |
| 12 | 15989900903341 |
| 13 | 161817863592868 |
| 14 | 1632050285251337 |
| 15 | 16420272919788800 |
| 16 | 164917283388807621 |
[1,28,497,7160,91581,1086708,12265177,133727440, 1422928661,14879566988,153661601457,1572610177320, 15989900903341,161817863592868,1632050285251337, 16420272919788800,164917283388807621] |