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| n | a(n) |
|---|---|
| 1 | 256 |
| 2 | 1060 |
| 3 | 5136 |
| 4 | 32920 |
| 5 | 118936 |
| 6 | 484704 |
| 7 | 3270240 |
| 8 | 11893600 |
| 9 | 48470400 |
| 10 | 327024000 |
| 11 | 1189360000 |
| 12 | 4847040000 |
| 13 | 32702400000 |
| 14 | 118936000000 |
| 15 | 484704000000 |
| 16 | 3270240000000 |
| 17 | 11893600000000 |
| 18 | 48470400000000 |
| 19 | 327024000000000 |
[256,1060,5136,32920,118936,484704,3270240, 11893600,48470400,327024000,1189360000,4847040000, 32702400000,118936000000,484704000000, 3270240000000,11893600000000,48470400000000, 327024000000000] |