n | a(n) |
---|---|
0 | 1 |
1 | 0 |
2 | -2 |
3 | -2 |
4 | -4 |
5 | -8 |
6 | -18 |
7 | -42 |
8 | -102 |
9 | -254 |
10 | -646 |
11 | -1670 |
12 | -4376 |
13 | -11596 |
14 | -31022 |
15 | -83670 |
16 | -227268 |
17 | -621144 |
18 | -1706934 |
19 | -4713558 |
20 | -13072764 |
21 | -36398568 |
22 | -101704038 |
23 | -285095118 |
24 | -801526446 |
25 | -2259520830 |
26 | -6385455594 |
27 | -18086805002 |
[1,0,-2,-2,-4,-8,-18,-42,-102,-254,-646,-1670, -4376,-11596,-31022,-83670,-227268,-621144, -1706934,-4713558,-13072764,-36398568,-101704038, -285095118,-801526446,-2259520830,-6385455594, -18086805002] |