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| n | a(n) |
|---|---|
| 0 | 2 |
| 1 | 20 |
| 2 | 210 |
| 3 | 2520 |
| 4 | 34650 |
| 5 | 540540 |
| 6 | 9459450 |
| 7 | 183783600 |
| 8 | 3928374450 |
| 9 | 91662070500 |
| 10 | 2319050383650 |
| 11 | 63246828645000 |
| 12 | 1849969737866250 |
| 13 | 57775977967207500 |
| 14 | 1918987839625106250 |
| 15 | 67548371954803740000 |
| 16 | 2511955082069264081250 |
[2,20,210,2520,34650,540540,9459450,183783600, 3928374450,91662070500,2319050383650, 63246828645000,1849969737866250,57775977967207500, 1918987839625106250,67548371954803740000, 2511955082069264081250] |