The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | -1 |
| 3 | 2 |
| 4 | -3 |
| 5 | 4 |
| 6 | -6 |
| 7 | 12 |
| 8 | -28 |
| 9 | 64 |
| 10 | -136 |
| 11 | 272 |
| 12 | -528 |
| 13 | 1024 |
| 14 | -2016 |
| 15 | 4032 |
| 16 | -8128 |
| 17 | 16383 |
| 18 | -32878 |
| 19 | 65621 |
| 20 | -130188 |
| 21 | 256158 |
| 22 | -497420 |
| 23 | 946352 |
| 24 | -1748000 |
| 25 | 3100078 |
| 26 | -5200300 |
| 27 | 8048666 |
| 28 | -10897033 |
| 29 | 10897061 |
| 30 | -435 |
| 31 | -41847869 |
| 32 | 161227527 |
| 33 | -461566314 |
| 34 | 1165457645 |
| 35 | -2740966304 |
[2,-1,2,-3,4,-6,12,-28,64,-136,272,-528,1024, -2016,4032,-8128,16383,-32878,65621,-130188, 256158,-497420,946352,-1748000,3100078,-5200300, 8048666,-10897033,10897061,-435,-41847869, 161227527,-461566314,1165457645,-2740966304] |