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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 11 |
| 3 | 170 |
| 4 | 3450 |
| 5 | 87864 |
| 6 | 2715720 |
| 7 | 99248400 |
| 8 | 4200210000 |
| 9 | 202383054720 |
| 10 | 10949741066880 |
| 11 | 657619863264000 |
| 12 | 43423960900320000 |
| 13 | 3127284944109849600 |
| 14 | 243957907264508236800 |
| 15 | 20493712266753293568000 |
| 16 | 1844490309401727187200000 |
| 17 | 177073768932670444843008000 |
| 18 | 18061662138488384327847936000 |
| 19 | 1950666948832313303630438400000 |
[1,11,170,3450,87864,2715720,99248400,4200210000, 202383054720,10949741066880,657619863264000, 43423960900320000,3127284944109849600, 243957907264508236800,20493712266753293568000, 1844490309401727187200000, 177073768932670444843008000, 18061662138488384327847936000, 1950666948832313303630438400000] |