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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 25 |
| 6 | 173 |
| 7 | 1794 |
| 8 | 20685 |
| 9 | 319727 |
| 10 | 6676539 |
| 11 | 232552310 |
| 12 | 11372993795 |
[1,1,1,1,25,173,1794,20685,319727,6676539, 232552310,11372993795] |