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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 12 |
| 2 | 75 |
| 3 | 330 |
| 4 | 1155 |
| 5 | 3432 |
| 6 | 9009 |
| 7 | 21450 |
| 8 | 47190 |
| 9 | 97240 |
| 10 | 189618 |
| 11 | 352716 |
| 12 | 629850 |
| 13 | 1085280 |
| 14 | 1812030 |
| 15 | 2941884 |
| 16 | 4657983 |
| 17 | 7210500 |
| 18 | 10935925 |
| 19 | 16280550 |
| 20 | 23828805 |
| 21 | 34337160 |
| 22 | 48774375 |
| 23 | 68368950 |
| 24 | 94664700 |
| 25 | 129585456 |
| 26 | 175509972 |
| 27 | 235358200 |
[1,12,75,330,1155,3432,9009,21450,47190,97240, 189618,352716,629850,1085280,1812030,2941884, 4657983,7210500,10935925,16280550,23828805, 34337160,48774375,68368950,94664700,129585456, 175509972,235358200] |