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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 3 |
| 4 | 16 |
| 5 | 30 |
| 6 | 480 |
| 7 | 1290 |
| 8 | 163200 |
| 9 | 471240 |
| 10 | 386400000 |
| 11 | 2269270080 |
| 12 | 12238171545600 |
| 13 | 149648961369600 |
| 14 | 8089070513113497600 |
| 15 | 160650421233958656000 |
| 16 | 91361407076595590705971200 |
[1,2,3,16,30,480,1290,163200,471240,386400000, 2269270080,12238171545600,149648961369600, 8089070513113497600,160650421233958656000, 91361407076595590705971200] |