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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 8 |
| 2 | 64 |
| 3 | 428 |
| 4 | 2556 |
| 5 | 13224 |
| 6 | 60600 |
| 7 | 250062 |
| 8 | 977026 |
| 9 | 3754472 |
| 10 | 14486158 |
| 11 | 56109736 |
| 12 | 220213038 |
| 13 | 875120922 |
| 14 | 3539254104 |
| 15 | 14534439529 |
| 16 | 60794185555 |
| 17 | 258385808222 |
| 18 | 1118113946883 |
| 19 | 4915589687030 |
| 20 | 21983704654711 |
| 21 | 99825770573061 |
| 22 | 460645444681024 |
| 23 | 2156595097630195 |
[1,8,64,428,2556,13224,60600,250062,977026, 3754472,14486158,56109736,220213038,875120922, 3539254104,14534439529,60794185555,258385808222, 1118113946883,4915589687030,21983704654711, 99825770573061,460645444681024,2156595097630195] |