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| n | a(n) |
|---|---|
| 1 | 8 |
| 2 | 66 |
| 3 | 244 |
| 4 | 2016 |
| 5 | 6576 |
| 6 | 54138 |
| 7 | 173428 |
| 8 | 1427040 |
| 9 | 4558536 |
| 10 | 37506738 |
| 11 | 119758148 |
| 12 | 985334832 |
| 13 | 3145930352 |
| 14 | 25883741898 |
| 15 | 82639468964 |
| 16 | 679931791152 |
| 17 | 2170826159272 |
| 18 | 17860880147874 |
| 19 | 57024624645332 |
| 20 | 469180811419968 |
| 21 | 1497958570841456 |
[8,66,244,2016,6576,54138,173428,1427040,4558536, 37506738,119758148,985334832,3145930352, 25883741898,82639468964,679931791152, 2170826159272,17860880147874,57024624645332, 469180811419968,1497958570841456] |