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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 16 |
| 3 | 3072 |
| 4 | 66060288 |
| 5 | 681869007912960 |
| 6 | 13963783542711369125068800 |
| 7 | 2305981313752949175455638153064349696000 |
| 8 | 12380897999371387785024422461502386865911933091803299840000 |
[2,16,3072,66060288,681869007912960, 13963783542711369125068800, 2305981313752949175455638153064349696000, 12380897999371387785024422461502386865911933091803\ 299840000] |