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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 14 |
| 2 | 168 |
| 3 | 2016 |
| 4 | 25200 |
| 5 | 332640 |
| 6 | 4656960 |
| 7 | 69189120 |
| 8 | 1089728640 |
| 9 | 18162144000 |
| 10 | 319653734400 |
| 11 | 5928123801600 |
| 12 | 115598414131200 |
| 13 | 2365321396838400 |
| 14 | 50685458503680000 |
| 15 | 1135354270482432000 |
| 16 | 26538906072526848000 |
| 17 | 646300418472124416000 |
| 18 | 16372943934627151872000 |
[1,14,168,2016,25200,332640,4656960,69189120, 1089728640,18162144000,319653734400,5928123801600, 115598414131200,2365321396838400, 50685458503680000,1135354270482432000, 26538906072526848000,646300418472124416000, 16372943934627151872000] |