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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 8 |
| 3 | 16 |
| 4 | 48 |
| 5 | 116 |
| 6 | 288 |
| 7 | 678 |
| 8 | 1600 |
| 9 | 3766 |
| 10 | 8704 |
| 11 | 20040 |
| 12 | 45904 |
| 13 | 104540 |
| 14 | 237268 |
| 15 | 536526 |
| 16 | 1209480 |
| 17 | 2719500 |
| 18 | 6099968 |
| 19 | 13653798 |
| 20 | 30504064 |
| 21 | 68032030 |
| 22 | 151493220 |
| 23 | 336863254 |
| 24 | 748075672 |
| 25 | 1659257392 |
| 26 | 3676182044 |
| 27 | 8136355808 |
| 28 | 17990500384 |
| 29 | 39743338382 |
[2,8,16,48,116,288,678,1600,3766,8704,20040,45904, 104540,237268,536526,1209480,2719500,6099968, 13653798,30504064,68032030,151493220,336863254, 748075672,1659257392,3676182044,8136355808, 17990500384,39743338382] |