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| n | a(n) |
|---|---|
| 1 | 28 |
| 2 | 70 |
| 3 | 148 |
| 4 | 298 |
| 5 | 592 |
| 6 | 1174 |
| 7 | 2332 |
| 8 | 4642 |
| 9 | 9256 |
| 10 | 18442 |
| 11 | 36736 |
| 12 | 73174 |
| 13 | 145756 |
| 14 | 290338 |
| 15 | 578344 |
| 16 | 1152046 |
| 17 | 2294836 |
| 18 | 4571230 |
| 19 | 9105724 |
| 20 | 18138274 |
| 21 | 36130792 |
| 22 | 71971246 |
| 23 | 143364148 |
| 24 | 285576250 |
| 25 | 568857664 |
| 26 | 1133144098 |
| 27 | 2257182472 |
| 28 | 4496226670 |
[28,70,148,298,592,1174,2332,4642,9256,18442, 36736,73174,145756,290338,578344,1152046,2294836, 4571230,9105724,18138274,36130792,71971246, 143364148,285576250,568857664,1133144098, 2257182472,4496226670] |