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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | -4 |
| 3 | 10 |
| 4 | -30 |
| 5 | 102 |
| 6 | -376 |
| 7 | 1462 |
| 8 | -5900 |
| 9 | 24470 |
| 10 | -103644 |
| 11 | 446382 |
| 12 | -1948854 |
| 13 | 8605290 |
| 14 | -38362200 |
| 15 | 172423770 |
| 16 | -780496110 |
| 17 | 3554991270 |
| 18 | -16281079900 |
| 19 | 74927379550 |
| 20 | -346328465930 |
| 21 | 1607078948690 |
| 22 | -7483861047480 |
| 23 | 34963419415650 |
| 24 | -163825013554400 |
| 25 | 769694347677002 |
[1,2,-4,10,-30,102,-376,1462,-5900,24470,-103644, 446382,-1948854,8605290,-38362200,172423770, -780496110,3554991270,-16281079900,74927379550, -346328465930,1607078948690,-7483861047480, 34963419415650,-163825013554400,769694347677002] |