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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 3 |
| 4 | 9 |
| 5 | 105 |
| 6 | 225 |
| 7 | 945 |
| 8 | 36225 |
| 9 | 76545 |
| 10 | 2253825 |
| 11 | 9511425 |
| 12 | 89345025 |
| 13 | 1526349825 |
| 14 | 26434433025 |
| 15 | 287969306625 |
| 16 | 12057038618625 |
| 17 | 179439357722625 |
| 18 | 5870438207258625 |
| 19 | 37882306735898625 |
| 20 | 1984203913277210625 |
| 21 | 11715811945983770625 |
| 22 | 982443713208463130625 |
| 23 | 15594453174317362970625 |
[0,1,3,9,105,225,945,36225,76545,2253825,9511425, 89345025,1526349825,26434433025,287969306625, 12057038618625,179439357722625,5870438207258625, 37882306735898625,1984203913277210625, 11715811945983770625,982443713208463130625, 15594453174317362970625] |