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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 2 |
| 2 | -3 |
| 3 | 10 |
| 4 | -50 |
| 5 | 348 |
| 6 | -2984 |
| 7 | 30392 |
| 8 | -362704 |
| 9 | 4961296 |
| 10 | -76245664 |
| 11 | 1300812544 |
| 12 | -24422250368 |
| 13 | 500336707648 |
| 14 | -11103109689216 |
| 15 | 265322822941056 |
| 16 | -6793379754870784 |
| 17 | 185540068027414784 |
| 18 | -5384094013002699264 |
[0,2,-3,10,-50,348,-2984,30392,-362704,4961296, -76245664,1300812544,-24422250368,500336707648, -11103109689216,265322822941056,-6793379754870784, 185540068027414784,-5384094013002699264] |