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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 12 |
| 4 | 252 |
| 5 | 1512 |
| 6 | 217728 |
| 7 | 1741824 |
| 8 | 548674560 |
| 9 | 28531077120 |
| 10 | 9244068986880 |
| 11 | 110928827842560 |
| 12 | 3130855237028413440 |
| 13 | 43831973318397788160 |
| 14 | 25247216631397125980160 |
| 15 | 14542396779684744564572160 |
| 16 | 142006504553621530673047142400 |
| 17 | 2556117081965187552114848563200 |
[1,3,12,252,1512,217728,1741824,548674560, 28531077120,9244068986880,110928827842560, 3130855237028413440,43831973318397788160, 25247216631397125980160, 14542396779684744564572160, 142006504553621530673047142400, 2556117081965187552114848563200] |