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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 4 |
| 4 | -9 |
| 5 | -20 |
| 6 | 55 |
| 7 | 210 |
| 8 | -1085 |
| 9 | -7000 |
| 10 | 53235 |
| 11 | 462350 |
| 12 | -4500265 |
| 13 | -48454980 |
| 14 | 571411295 |
| 15 | 7321388410 |
| 16 | -101249656725 |
| 17 | -1502852293040 |
| 18 | 23827244817355 |
| 19 | 401839065437670 |
| 20 | -7182224591785985 |
| 21 | -135607710526966300 |
| 22 | 2696935204638786615 |
| 23 | 56349204870460046930 |
| 24 | -1234002202313888987245 |
[1,1,4,-9,-20,55,210,-1085,-7000,53235,462350, -4500265,-48454980,571411295,7321388410, -101249656725,-1502852293040,23827244817355, 401839065437670,-7182224591785985, -135607710526966300,2696935204638786615, 56349204870460046930,-1234002202313888987245] |