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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 6 |
| 2 | 360 |
| 3 | 3024 |
| 4 | 1814400 |
| 5 | 887040 |
| 6 | 72648576000 |
| 7 | 784604620800 |
| 8 | 13857951744000 |
| 9 | 196503623737344000 |
| 10 | 8430005458332057600000 |
| 11 | 1249560422395084800000 |
| 12 | 747275354440475148288000000 |
| 13 | 25197383852207757066240000 |
| 14 | 2105181427080881417748480000000 |
| 15 | 154617478967448121358942208000000 |
[1,6,360,3024,1814400,887040,72648576000, 784604620800,13857951744000,196503623737344000, 8430005458332057600000,1249560422395084800000, 747275354440475148288000000, 25197383852207757066240000, 2105181427080881417748480000000, 154617478967448121358942208000000] |