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| n | a(n) |
|---|---|
| 3 | 0 |
| 4 | 0 |
| 5 | 4 |
| 6 | 6 |
| 7 | 8 |
| 8 | 24 |
| 9 | 55 |
| 10 | 122 |
| 11 | 284 |
| 12 | 640 |
| 13 | 1499 |
| 14 | 3523 |
| 15 | 8555 |
| 16 | 21207 |
| 17 | 52142 |
| 18 | 131769 |
| 19 | 340170 |
| 20 | 873080 |
| 21 | 2262490 |
| 22 | 5947043 |
| 23 | 15649920 |
| 24 | 41289048 |
| 25 | 109539183 |
| 26 | 291179345 |
| 27 | 774884877 |
| 28 | 2066087278 |
| 29 | 5516257587 |
| 30 | 14741851755 |
| 31 | 39438287815 |
[0,0,4,6,8,24,55,122,284,640,1499,3523,8555,21207, 52142,131769,340170,873080,2262490,5947043, 15649920,41289048,109539183,291179345,774884877, 2066087278,5516257587,14741851755,39438287815] |