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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 6 |
| 3 | 14 |
| 4 | 30 |
| 5 | 60 |
| 6 | 118 |
| 7 | 236 |
| 8 | 460 |
| 9 | 914 |
| 10 | 1810 |
| 11 | 3608 |
| 12 | 7158 |
| 13 | 14310 |
| 14 | 28504 |
| 15 | 56978 |
| 16 | 113778 |
| 17 | 227484 |
| 18 | 454534 |
| 19 | 909050 |
| 20 | 1817232 |
| 21 | 3634344 |
| 22 | 7267198 |
| 23 | 14534120 |
| 24 | 29064982 |
| 25 | 58129922 |
| 26 | 116253394 |
| 27 | 232506236 |
| 28 | 465000468 |
| 29 | 929999880 |
| 30 | 1859974762 |
| 31 | 3719949488 |
| 32 | 7439848936 |
| 33 | 14879695742 |
[2,6,14,30,60,118,236,460,914,1810,3608,7158, 14310,28504,56978,113778,227484,454534,909050, 1817232,3634344,7267198,14534120,29064982, 58129922,116253394,232506236,465000468,929999880, 1859974762,3719949488,7439848936,14879695742] |