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| n | a(n) |
|---|---|
| 1 | 10 |
| 2 | 100 |
| 3 | 390 |
| 4 | 1950 |
| 5 | 9072 |
| 6 | 43498 |
| 7 | 206514 |
| 8 | 982940 |
| 9 | 4672690 |
| 10 | 22223478 |
| 11 | 105684192 |
| 12 | 502611290 |
| 13 | 2390250122 |
| 14 | 11367287780 |
| 15 | 54059152686 |
| 16 | 257088257194 |
| 17 | 1222630168560 |
| 18 | 5814441801566 |
| 19 | 27651641179470 |
| 20 | 131502438430740 |
| 21 | 625383900547134 |
[10,100,390,1950,9072,43498,206514,982940,4672690, 22223478,105684192,502611290,2390250122, 11367287780,54059152686,257088257194, 1222630168560,5814441801566,27651641179470, 131502438430740,625383900547134] |