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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 8 |
| 3 | 16 |
| 4 | 44 |
| 5 | 112 |
| 6 | 252 |
| 7 | 564 |
| 8 | 1276 |
| 9 | 2840 |
| 10 | 6220 |
| 11 | 13532 |
| 12 | 29292 |
| 13 | 63024 |
| 14 | 134876 |
| 15 | 287428 |
| 16 | 610268 |
| 17 | 1291336 |
| 18 | 2724204 |
| 19 | 5731500 |
| 20 | 12029260 |
| 21 | 25191008 |
| 22 | 52646908 |
| 23 | 109823636 |
| 24 | 228707004 |
| 25 | 475533432 |
| 26 | 987305612 |
| 27 | 2047088764 |
| 28 | 4239132716 |
[1,0,8,16,44,112,252,564,1276,2840,6220,13532, 29292,63024,134876,287428,610268,1291336,2724204, 5731500,12029260,25191008,52646908,109823636, 228707004,475533432,987305612,2047088764, 4239132716] |