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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 9 |
| 3 | 126 |
| 4 | 1920 |
| 5 | 27190 |
| 6 | 347168 |
| 7 | 3990467 |
| 8 | 42744527 |
| 9 | 440764556 |
| 10 | 4464045276 |
| 11 | 44863859589 |
| 12 | 449488519847 |
| 13 | 4498059105204 |
| 14 | 44992451829730 |
| 15 | 449969622539954 |
| 16 | 4499873022468708 |
| 17 | 44999449703306768 |
| 18 | 449997540235466340 |
| 19 | 4499988731927483569 |
| 20 | 44999947410278947807 |
[1,9,126,1920,27190,347168,3990467,42744527, 440764556,4464045276,44863859589,449488519847, 4498059105204,44992451829730,449969622539954, 4499873022468708,44999449703306768, 449997540235466340,4499988731927483569, 44999947410278947807] |