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| n | a(n) |
|---|---|
| 1 | -1 |
| 2 | 0 |
| 3 | 2 |
| 4 | -3 |
| 5 | 0 |
| 6 | 6 |
| 7 | -9 |
| 8 | 1 |
| 9 | 17 |
| 10 | -27 |
| 11 | 5 |
| 12 | 48 |
| 13 | -81 |
| 14 | 21 |
| 15 | 135 |
| 16 | -242 |
| 17 | 80 |
| 18 | 378 |
| 19 | -721 |
| 20 | 288 |
| 21 | 1053 |
| 22 | -2142 |
| 23 | 999 |
| 24 | 2917 |
| 25 | -6346 |
| 26 | 3375 |
| 27 | 8030 |
| 28 | -18750 |
| 29 | 11178 |
| 30 | 21948 |
| 31 | -55251 |
| 32 | 36451 |
| 33 | 59498 |
| 34 | -162378 |
| 35 | 117383 |
| 36 | 159744 |
| 37 | -475956 |
| 38 | 374097 |
| 39 | 423981 |
| 40 | -1391417 |
| 41 | 1181789 |
| 42 | 1109565 |
[-1,0,2,-3,0,6,-9,1,17,-27,5,48,-81,21,135,-242, 80,378,-721,288,1053,-2142,999,2917,-6346,3375, 8030,-18750,11178,21948,-55251,36451,59498, -162378,117383,159744,-475956,374097,423981, -1391417,1181789,1109565] |