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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 8 |
| 4 | 12 |
| 5 | 60 |
| 6 | 84 |
| 7 | 444 |
| 8 | 612 |
| 9 | 3276 |
| 10 | 4500 |
| 11 | 24156 |
| 12 | 33156 |
| 13 | 178092 |
| 14 | 244404 |
| 15 | 1312956 |
| 16 | 1801764 |
| 17 | 9679500 |
| 18 | 13283028 |
| 19 | 71360028 |
| 20 | 97926084 |
| 21 | 526086252 |
| 22 | 721938420 |
| 23 | 3878455932 |
| 24 | 5322332772 |
| 25 | 28593068364 |
| 26 | 39237733908 |
| 27 | 210796144092 |
[1,2,8,12,60,84,444,612,3276,4500,24156,33156, 178092,244404,1312956,1801764,9679500,13283028, 71360028,97926084,526086252,721938420,3878455932, 5322332772,28593068364,39237733908,210796144092] |