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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | -3 |
| 3 | 9 |
| 4 | -30 |
| 5 | 106 |
| 6 | -385 |
| 7 | 1421 |
| 8 | -5304 |
| 9 | 19966 |
| 10 | -75658 |
| 11 | 288222 |
| 12 | -1102790 |
| 13 | 4234868 |
| 14 | -16312773 |
| 15 | 63003869 |
| 16 | -243896960 |
| 17 | 946066678 |
| 18 | -3676303578 |
| 19 | 14308370014 |
| 20 | -55768166380 |
| 21 | 217640082188 |
| 22 | -850345208538 |
| 23 | 3325907590274 |
| 24 | -13020993588680 |
[0,1,-3,9,-30,106,-385,1421,-5304,19966,-75658, 288222,-1102790,4234868,-16312773,63003869, -243896960,946066678,-3676303578,14308370014, -55768166380,217640082188,-850345208538, 3325907590274,-13020993588680] |