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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 2 |
| 3 | 12 |
| 4 | 216 |
| 5 | 5280 |
| 6 | 190800 |
| 7 | 9344160 |
| 8 | 598066560 |
| 9 | 48443028480 |
| 10 | 4844306476800 |
| 11 | 586161043776000 |
| 12 | 84407190782745600 |
| 13 | 14264815236056985600 |
| 14 | 2795903786354347468800 |
| 15 | 629078351928420506112000 |
| 16 | 161044058093696572354560000 |
| 17 | 46541732789077953723039744000 |
[1,0,2,12,216,5280,190800,9344160,598066560, 48443028480,4844306476800,586161043776000, 84407190782745600,14264815236056985600, 2795903786354347468800,629078351928420506112000, 161044058093696572354560000, 46541732789077953723039744000] |