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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 5 |
| 2 | 45 |
| 3 | 570 |
| 4 | 9270 |
| 5 | 183840 |
| 6 | 4299360 |
| 7 | 115795920 |
| 8 | 3528915840 |
| 9 | 120032889840 |
| 10 | 4507313333040 |
| 11 | 185185602462240 |
| 12 | 8262852630732000 |
| 13 | 397873645339668480 |
| 14 | 20563762111640910720 |
| 15 | 1135441077379757372160 |
| 16 | 66703342626913255770240 |
| 17 | 4154100873615633462894720 |
[1,5,45,570,9270,183840,4299360,115795920, 3528915840,120032889840,4507313333040, 185185602462240,8262852630732000, 397873645339668480,20563762111640910720, 1135441077379757372160,66703342626913255770240, 4154100873615633462894720] |