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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 3 |
| 3 | -5 |
| 4 | 14 |
| 5 | -45 |
| 6 | 154 |
| 7 | -546 |
| 8 | 1980 |
| 9 | -7293 |
| 10 | 27170 |
| 11 | -102102 |
| 12 | 386308 |
| 13 | -1469650 |
| 14 | 5616324 |
| 15 | -21544100 |
| 16 | 82907640 |
| 17 | -319929885 |
| 18 | 1237518450 |
| 19 | -4796857230 |
| 20 | 18627909300 |
| 21 | -72457790790 |
| 22 | 282257178060 |
| 23 | -1100982015900 |
| 24 | 4299680491080 |
| 25 | -16809921068850 |
| 26 | 65785111513524 |
| 27 | -257683159276956 |
[0,1,3,-5,14,-45,154,-546,1980,-7293,27170, -102102,386308,-1469650,5616324,-21544100, 82907640,-319929885,1237518450,-4796857230, 18627909300,-72457790790,282257178060, -1100982015900,4299680491080,-16809921068850, 65785111513524,-257683159276956] |