The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | -1 |
| 2 | 1 |
| 3 | -2 |
| 4 | 2 |
| 5 | -6 |
| 6 | 5 |
| 7 | -21 |
| 8 | 14 |
| 9 | -79 |
| 10 | 43 |
| 11 | -308 |
| 12 | 147 |
| 13 | -1221 |
| 14 | 571 |
| 15 | -4868 |
| 16 | 2514 |
| 17 | -19388 |
| 18 | 12144 |
| 19 | -76814 |
| 20 | 61681 |
| 21 | -302007 |
| 22 | 318597 |
| 23 | -1177274 |
| 24 | 1640389 |
| 25 | -4553897 |
| 26 | 8333655 |
| 27 | -17533572 |
| 28 | 41583474 |
| 29 | -67607944 |
| 30 | 203455513 |
| 31 | -263678119 |
| 32 | 975780382 |
[1,-1,1,-2,2,-6,5,-21,14,-79,43,-308,147,-1221, 571,-4868,2514,-19388,12144,-76814,61681,-302007, 318597,-1177274,1640389,-4553897,8333655, -17533572,41583474,-67607944,203455513,-263678119, 975780382] |