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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 8 |
| 3 | 0 |
| 4 | 27 |
| 5 | 27 |
| 6 | 154 |
| 7 | 272 |
| 8 | 1117 |
| 9 | 2321 |
| 10 | 7299 |
| 11 | 18275 |
| 12 | 54627 |
| 13 | 150925 |
| 14 | 405606 |
| 15 | 1155080 |
| 16 | 3116256 |
| 17 | 8868340 |
| 18 | 23994371 |
| 19 | 67730571 |
| 20 | 185335502 |
| 21 | 518769588 |
| 22 | 1425654497 |
| 23 | 3971507983 |
| 24 | 10973327639 |
| 25 | 30469831297 |
| 26 | 84329766549 |
| 27 | 233791763797 |
[0,8,0,27,27,154,272,1117,2321,7299,18275,54627, 150925,405606,1155080,3116256,8868340,23994371, 67730571,185335502,518769588,1425654497, 3971507983,10973327639,30469831297,84329766549, 233791763797] |