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| n | a(n) |
|---|---|
| 1 | 28 |
| 2 | 784 |
| 3 | 4344 |
| 4 | 46800 |
| 5 | 366330 |
| 6 | 3327954 |
| 7 | 28188778 |
| 8 | 247024548 |
| 9 | 2129817756 |
| 10 | 18503218016 |
| 11 | 160144863388 |
| 12 | 1388528077986 |
| 13 | 12029107363320 |
| 14 | 104255340840714 |
| 15 | 903395668109660 |
| 16 | 7828846025215230 |
| 17 | 67841580292509632 |
| 18 | 587899815684673466 |
[28,784,4344,46800,366330,3327954,28188778, 247024548,2129817756,18503218016,160144863388, 1388528077986,12029107363320,104255340840714, 903395668109660,7828846025215230, 67841580292509632,587899815684673466] |