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| n | a(n) |
|---|---|
| 0 | 2 |
| 1 | 10 |
| 2 | 22 |
| 3 | 64 |
| 4 | 146 |
| 5 | 324 |
| 6 | 708 |
| 7 | 1428 |
| 8 | 2888 |
| 9 | 5650 |
| 10 | 10886 |
| 11 | 20574 |
| 12 | 38416 |
| 13 | 70716 |
| 14 | 129370 |
| 15 | 232726 |
| 16 | 417502 |
| 17 | 741758 |
| 18 | 1308048 |
| 19 | 2292274 |
| 20 | 3991032 |
| 21 | 6918986 |
| 22 | 11940104 |
| 23 | 20475352 |
| 24 | 34976158 |
| 25 | 59511690 |
| 26 | 100984886 |
| 27 | 170771982 |
| 28 | 287205324 |
[2,10,22,64,146,324,708,1428,2888,5650,10886, 20574,38416,70716,129370,232726,417502,741758, 1308048,2292274,3991032,6918986,11940104,20475352, 34976158,59511690,100984886,170771982,287205324] |