The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | -1 |
| 3 | 7 |
| 4 | -13 |
| 5 | 36 |
| 6 | -67 |
| 7 | 141 |
| 8 | -269 |
| 9 | 547 |
| 10 | -1076 |
| 11 | 2146 |
| 12 | -4231 |
| 13 | 8399 |
| 14 | -16661 |
| 15 | 33177 |
| 16 | -66109 |
| 17 | 131921 |
| 18 | -263353 |
| 19 | 526054 |
| 20 | -1051108 |
| 21 | 2100840 |
| 22 | -4199614 |
| 23 | 8396289 |
| 24 | -16788239 |
| 25 | 33570311 |
| 26 | -67131715 |
| 27 | 134250784 |
| 28 | -268483361 |
| 29 | 536940598 |
| 30 | -1073843297 |
| 31 | 2147631641 |
| 32 | -4295183165 |
| 33 | 8590249609 |
| 34 | -17180328793 |
[1,-1,7,-13,36,-67,141,-269,547,-1076,2146,-4231, 8399,-16661,33177,-66109,131921,-263353,526054, -1051108,2100840,-4199614,8396289,-16788239, 33570311,-67131715,134250784,-268483361,536940598, -1073843297,2147631641,-4295183165,8590249609, -17180328793] |