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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 6 |
| 3 | 76 |
| 4 | 1170 |
| 5 | 18208 |
| 6 | 278758 |
| 7 | 4294812 |
| 8 | 66052162 |
| 9 | 1016260448 |
| 10 | 15634778470 |
| 11 | 240537044748 |
| 12 | 3700602618386 |
| 13 | 56932811822272 |
| 14 | 875896777768582 |
| 15 | 13475447374606748 |
| 16 | 207316306566902018 |
| 17 | 3189508270154101568 |
[0,6,76,1170,18208,278758,4294812,66052162, 1016260448,15634778470,240537044748,3700602618386, 56932811822272,875896777768582,13475447374606748, 207316306566902018,3189508270154101568] |