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| n | a(n) |
|---|---|
| 1 | 390 |
| 2 | 2100 |
| 3 | 10080 |
| 4 | 50310 |
| 5 | 247800 |
| 6 | 1226040 |
| 7 | 6056600 |
| 8 | 29936040 |
| 9 | 147935520 |
| 10 | 731109730 |
| 11 | 3613107680 |
| 12 | 17855974900 |
| 13 | 88243889790 |
| 14 | 436100216050 |
| 15 | 2155200833200 |
| 16 | 10650972655340 |
| 17 | 52636955728500 |
| 18 | 260131094865980 |
| 19 | 1285564199904440 |
[390,2100,10080,50310,247800,1226040,6056600, 29936040,147935520,731109730,3613107680, 17855974900,88243889790,436100216050, 2155200833200,10650972655340,52636955728500, 260131094865980,1285564199904440] |