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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 4 |
| 4 | 37 |
| 5 | 667 |
| 6 | 21886 |
| 7 | 1262719 |
| 8 | 125387767 |
| 9 | 21009091072 |
| 10 | 5809425721381 |
| 11 | 2596693747042999 |
| 12 | 1844571022305443422 |
[1,1,4,37,667,21886,1262719,125387767,21009091072, 5809425721381,2596693747042999, 1844571022305443422] |