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| n | a(n) |
|---|---|
| 1 | -1 |
| 2 | 3 |
| 3 | -23 |
| 4 | 226 |
| 5 | -2800 |
| 6 | 42576 |
| 7 | -763220 |
| 8 | 15734614 |
| 9 | -366715248 |
| 10 | 9533817400 |
| 11 | -273549419552 |
| 12 | 8586984284446 |
| 13 | -292755986184548 |
| 14 | 10772849583399474 |
| 15 | -425587711650564816 |
| 16 | 17966217347001535764 |
| 17 | -807152054953801845760 |
| 18 | 38451365602113352159320 |
| 19 | -1936082850634342992601636 |
[-1,3,-23,226,-2800,42576,-763220,15734614, -366715248,9533817400,-273549419552,8586984284446, -292755986184548,10772849583399474, -425587711650564816,17966217347001535764, -807152054953801845760,38451365602113352159320, -1936082850634342992601636] |