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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | -11 |
| 2 | 55 |
| 3 | -176 |
| 4 | 451 |
| 5 | -1078 |
| 6 | 2453 |
| 7 | -5181 |
| 8 | 10329 |
| 9 | -19954 |
| 10 | 37455 |
| 11 | -68135 |
| 12 | 120725 |
| 13 | -209583 |
| 14 | 357258 |
| 15 | -598136 |
| 16 | 985072 |
| 17 | -1599807 |
| 18 | 2565365 |
| 19 | -4063191 |
| 20 | 6362323 |
| 21 | -9860851 |
| 22 | 15138013 |
| 23 | -23027730 |
| 24 | 34729959 |
| 25 | -51965067 |
| 26 | 77174735 |
[1,-11,55,-176,451,-1078,2453,-5181,10329,-19954, 37455,-68135,120725,-209583,357258,-598136,985072, -1599807,2565365,-4063191,6362323,-9860851, 15138013,-23027730,34729959,-51965067,77174735] |