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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | -1 |
| 3 | -2 |
| 4 | -2 |
| 5 | 0 |
| 6 | 2 |
| 7 | 4 |
| 8 | 3 |
| 9 | 0 |
| 10 | -1 |
| 11 | 6 |
| 12 | 28 |
| 13 | 72 |
| 14 | 139 |
| 15 | 242 |
| 16 | 407 |
| 17 | 722 |
| 18 | 1215 |
| 19 | 2348 |
| 20 | 3753 |
| 21 | 7186 |
| 22 | 9558 |
| 23 | 21800 |
| 24 | 16576 |
| 25 | 61234 |
| 26 | -7978 |
| 27 | 226136 |
| 28 | -446034 |
| 29 | 1118180 |
| 30 | -3180033 |
| 31 | 6428640 |
| 32 | -24607343 |
| 33 | 56904504 |
| 34 | -176451720 |
| 35 | 379824634 |
| 36 | -1133204742 |
| 37 | 3043377452 |
| 38 | -9446665098 |
| 39 | 25288847986 |
[1,0,-1,-2,-2,0,2,4,3,0,-1,6,28,72,139,242,407, 722,1215,2348,3753,7186,9558,21800,16576,61234, -7978,226136,-446034,1118180,-3180033,6428640, -24607343,56904504,-176451720,379824634, -1133204742,3043377452,-9446665098,25288847986] |