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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | -1 |
| 2 | -1 |
| 3 | -1 |
| 4 | -1 |
| 5 | -2 |
| 6 | -4 |
| 7 | -8 |
| 8 | -17 |
| 9 | -37 |
| 10 | -82 |
| 11 | -185 |
| 12 | -423 |
| 13 | -978 |
| 14 | -2283 |
| 15 | -5373 |
| 16 | -12735 |
| 17 | -30372 |
| 18 | -72832 |
| 19 | -175502 |
| 20 | -424748 |
| 21 | -1032004 |
| 22 | -2516347 |
| 23 | -6155441 |
| 24 | -15101701 |
| 25 | -37150472 |
| 26 | -91618049 |
| 27 | -226460893 |
| 28 | -560954047 |
| 29 | -1392251012 |
| 30 | -3461824644 |
| 31 | -8622571758 |
| 32 | -21511212261 |
[1,-1,-1,-1,-1,-2,-4,-8,-17,-37,-82,-185,-423, -978,-2283,-5373,-12735,-30372,-72832,-175502, -424748,-1032004,-2516347,-6155441,-15101701, -37150472,-91618049,-226460893,-560954047, -1392251012,-3461824644,-8622571758,-21511212261] |