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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 12 |
| 2 | 168 |
| 3 | 2464 |
| 4 | 36960 |
| 5 | 561792 |
| 6 | 8614144 |
| 7 | 132903936 |
| 8 | 2060011008 |
| 9 | 32044615680 |
| 10 | 499896004608 |
| 11 | 7816555708416 |
| 12 | 122459372765184 |
| 13 | 1921670157238272 |
| 14 | 30197673899458560 |
| 15 | 475110069351481344 |
| 16 | 7482983592285831168 |
| 17 | 117967035454858985472 |
| 18 | 1861257670509997326336 |
[1,12,168,2464,36960,561792,8614144,132903936, 2060011008,32044615680,499896004608,7816555708416, 122459372765184,1921670157238272, 30197673899458560,475110069351481344, 7482983592285831168,117967035454858985472, 1861257670509997326336] |