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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 2 |
| 4 | 2 |
| 5 | 6 |
| 6 | 12 |
| 7 | 28 |
| 8 | 48 |
| 9 | 106 |
| 10 | 198 |
| 11 | 414 |
| 12 | 800 |
| 13 | 1644 |
| 14 | 3236 |
| 15 | 6546 |
| 16 | 12982 |
| 17 | 26130 |
| 18 | 52048 |
| 19 | 104404 |
| 20 | 208372 |
| 21 | 417390 |
| 22 | 833930 |
| 23 | 1669102 |
| 24 | 3336476 |
| 25 | 6675512 |
| 26 | 13347600 |
| 27 | 26700226 |
| 28 | 53393562 |
| 29 | 106797302 |
| 30 | 213580904 |
| 31 | 427181968 |
| 32 | 854336432 |
| 33 | 1708713470 |
| 34 | 3417372070 |
| 35 | 6834824970 |
[0,0,2,2,6,12,28,48,106,198,414,800,1644,3236, 6546,12982,26130,52048,104404,208372,417390, 833930,1669102,3336476,6675512,13347600,26700226, 53393562,106797302,213580904,427181968,854336432, 1708713470,3417372070,6834824970] |