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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 12 |
| 2 | 88 |
| 3 | 608 |
| 4 | 4160 |
| 5 | 28416 |
| 6 | 194048 |
| 7 | 1325056 |
| 8 | 9048064 |
| 9 | 61784064 |
| 10 | 421888000 |
| 11 | 2880831488 |
| 12 | 19671547904 |
| 13 | 134325731328 |
| 14 | 917233467392 |
| 15 | 6263261888512 |
| 16 | 42768227368960 |
| 17 | 292039723843584 |
| 18 | 1994171971796992 |
| 19 | 13617057983627264 |
[1,12,88,608,4160,28416,194048,1325056,9048064, 61784064,421888000,2880831488,19671547904, 134325731328,917233467392,6263261888512, 42768227368960,292039723843584,1994171971796992, 13617057983627264] |