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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 2 |
| 3 | 339720 |
| 4 | 549023310936 |
| 5 | 4383995385521886720 |
| 6 | 131828993822765959468851600 |
| 7 | 12202002913678756821228939869239920 |
| 8 | 2988325485815656468293009880545684170044800 |
| 9 | 1723427149081248135793318785599849462668815779427840 |
[1,0,2,339720,549023310936,4383995385521886720, 131828993822765959468851600, 12202002913678756821228939869239920, 2988325485815656468293009880545684170044800, 17234271490812481357933187855998494626688157794278\ 40] |