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| n | a(n) |
|---|---|
| 1 | -2 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | -4 |
| 6 | 10 |
| 7 | -20 |
| 8 | 36 |
| 9 | -64 |
| 10 | 120 |
| 11 | -240 |
| 12 | 496 |
| 13 | -1024 |
| 14 | 2080 |
| 15 | -4159 |
| 16 | 8240 |
| 17 | -16248 |
| 18 | 31824 |
| 19 | -61403 |
| 20 | 115292 |
| 21 | -207670 |
| 22 | 352716 |
| 23 | -550430 |
| 24 | 748144 |
| 25 | -748144 |
| 26 | 0 |
| 27 | 2848366 |
| 28 | -10897032 |
| 29 | 30955332 |
| 30 | -77558759 |
| 31 | 181129040 |
| 32 | -404458736 |
| 33 | 875889376 |
| 34 | -1855921143 |
| 35 | 3870685664 |
[-2,0,0,1,-4,10,-20,36,-64,120,-240,496,-1024, 2080,-4159,8240,-16248,31824,-61403,115292, -207670,352716,-550430,748144,-748144,0,2848366, -10897032,30955332,-77558759,181129040,-404458736, 875889376,-1855921143,3870685664] |