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| n | a(n) |
|---|---|
| 2 | 1 |
| 3 | 4 |
| 4 | 31 |
| 5 | 391 |
| 6 | 7261 |
| 7 | 185956 |
| 8 | 6271189 |
| 9 | 269066701 |
| 10 | 14300511481 |
| 11 | 921666527596 |
| 12 | 70789188893611 |
| 13 | 6386088654729499 |
| 14 | 668423261212035421 |
| 15 | 80325071500899911596 |
| 16 | 10981857825124725031081 |
| 17 | 1694577083441728891610041 |
[1,4,31,391,7261,185956,6271189,269066701, 14300511481,921666527596,70789188893611, 6386088654729499,668423261212035421, 80325071500899911596,10981857825124725031081, 1694577083441728891610041] |