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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 1 |
| 6 | 9 |
| 7 | 49 |
| 8 | 253 |
| 9 | 1201 |
| 10 | 4573 |
| 11 | 30217 |
| 12 | 286533 |
| 13 | 2941009 |
| 14 | 37746461 |
| 15 | 678979449 |
| 16 | 14880214645 |
| 17 | 369497873441 |
[1,1,1,1,1,9,49,253,1201,4573,30217,286533, 2941009,37746461,678979449,14880214645, 369497873441] |