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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 7 |
| 2 | 65 |
| 3 | 583 |
| 4 | 5249 |
| 5 | 47239 |
| 6 | 425153 |
| 7 | 3826375 |
| 8 | 34437377 |
| 9 | 309936391 |
| 10 | 2789427521 |
| 11 | 25104847687 |
| 12 | 225943629185 |
| 13 | 2033492662663 |
| 14 | 18301433963969 |
| 15 | 164712905675719 |
| 16 | 1482416151081473 |
| 17 | 13341745359733255 |
| 18 | 120075708237599297 |
[1,7,65,583,5249,47239,425153,3826375,34437377, 309936391,2789427521,25104847687,225943629185, 2033492662663,18301433963969,164712905675719, 1482416151081473,13341745359733255, 120075708237599297] |