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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 7 |
| 4 | 66 |
| 5 | 3061 |
| 6 | 1095266 |
| 7 | 3906746485 |
| 8 | 165835140118904 |
| 9 | 96867653699340061187 |
| 10 | 883158060528372369857672080 |
| 11 | 140546577721904223563711600192372503 |
[1,1,2,7,66,3061,1095266,3906746485, 165835140118904,96867653699340061187, 883158060528372369857672080, 140546577721904223563711600192372503] |