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| n | a(n) |
|---|---|
| 1 | 42 |
| 2 | 1764 |
| 3 | 6216 |
| 4 | 21904 |
| 5 | 126688 |
| 6 | 732736 |
| 7 | 3773248 |
| 8 | 19430464 |
| 9 | 105642128 |
| 10 | 574369156 |
| 11 | 3050871800 |
| 12 | 16205290000 |
| 13 | 87703589600 |
| 14 | 474654858304 |
| 15 | 2537509425088 |
| 16 | 13565549724736 |
| 17 | 73283287813072 |
| 18 | 395888141775844 |
| 19 | 2122391971076888 |
[42,1764,6216,21904,126688,732736,3773248, 19430464,105642128,574369156,3050871800, 16205290000,87703589600,474654858304, 2537509425088,13565549724736,73283287813072, 395888141775844,2122391971076888] |