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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | -2 |
| 2 | 5 |
| 3 | -11 |
| 4 | 27 |
| 5 | -70 |
| 6 | 188 |
| 7 | -502 |
| 8 | 1355 |
| 9 | -3712 |
| 10 | 10269 |
| 11 | -28546 |
| 12 | 79777 |
| 13 | -224153 |
| 14 | 632581 |
| 15 | -1791644 |
| 16 | 5091109 |
| 17 | -14510079 |
| 18 | 41464784 |
| 19 | -118773034 |
| 20 | 340950420 |
| 21 | -980660721 |
| 22 | 2825700987 |
| 23 | -8155455450 |
| 24 | 23573749136 |
| 25 | -68236663474 |
| 26 | 197774787066 |
| 27 | -573915774310 |
| 28 | 1667300177595 |
[1,-2,5,-11,27,-70,188,-502,1355,-3712,10269, -28546,79777,-224153,632581,-1791644,5091109, -14510079,41464784,-118773034,340950420, -980660721,2825700987,-8155455450,23573749136, -68236663474,197774787066,-573915774310, 1667300177595] |