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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 12 |
| 2 | 82 |
| 3 | 488 |
| 4 | 2756 |
| 5 | 15216 |
| 6 | 83144 |
| 7 | 452128 |
| 8 | 2453008 |
| 9 | 13294272 |
| 10 | 72012064 |
| 11 | 389976704 |
| 12 | 2111644736 |
| 13 | 11433484032 |
| 14 | 61904845952 |
| 15 | 335169991168 |
| 16 | 1814692086016 |
| 17 | 9825156811776 |
| 18 | 53195565289984 |
| 19 | 288012326955008 |
[1,12,82,488,2756,15216,83144,452128,2453008, 13294272,72012064,389976704,2111644736, 11433484032,61904845952,335169991168, 1814692086016,9825156811776,53195565289984, 288012326955008] |