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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 70 |
| 3 | 34650 |
| 4 | 63063000 |
| 5 | 303526299000 |
| 6 | 3187068420047305 |
| 7 | 64239844119903312514 |
[1,1,70,34650,63063000,303526299000, 3187068420047305,64239844119903312514] |