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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 5 |
| 3 | 64 |
| 4 | 1107 |
| 5 | 160160 |
| 6 | 5713367 |
| 7 | 889747443 |
| 8 | 62837596341 |
| 9 | 11671262491586 |
| 10 | 3090090680653053 |
| 11 | 635672008069583520 |
| 12 | 278356729040728193703 |
[1,2,5,64,1107,160160,5713367,889747443, 62837596341,11671262491586,3090090680653053, 635672008069583520,278356729040728193703] |