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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 8 |
| 4 | 19 |
| 5 | 79 |
| 6 | 188 |
| 7 | 782 |
| 8 | 1861 |
| 9 | 7741 |
| 10 | 18422 |
| 11 | 76628 |
| 12 | 182359 |
| 13 | 758539 |
| 14 | 1805168 |
| 15 | 7508762 |
| 16 | 17869321 |
| 17 | 74329081 |
| 18 | 176888042 |
| 19 | 735782048 |
| 20 | 1751011099 |
| 21 | 7283491399 |
| 22 | 17333222948 |
| 23 | 72099131942 |
| 24 | 171581218381 |
| 25 | 713707828021 |
| 26 | 1698478960862 |
| 27 | 7064979148268 |
| 28 | 16813208390239 |
[1,2,8,19,79,188,782,1861,7741,18422,76628,182359, 758539,1805168,7508762,17869321,74329081, 176888042,735782048,1751011099,7283491399, 17333222948,72099131942,171581218381,713707828021, 1698478960862,7064979148268,16813208390239] |