The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | -1 |
| 2 | 2 |
| 3 | -3 |
| 4 | 6 |
| 5 | -10 |
| 6 | 18 |
| 7 | -31 |
| 8 | 55 |
| 9 | -96 |
| 10 | 169 |
| 11 | -296 |
| 12 | 520 |
| 13 | -912 |
| 14 | 1601 |
| 15 | -2809 |
| 16 | 4930 |
| 17 | -8651 |
| 18 | 15182 |
| 19 | -26642 |
| 20 | 46754 |
| 21 | -82047 |
| 22 | 143983 |
| 23 | -252672 |
| 24 | 443409 |
| 25 | -778128 |
| 26 | 1365520 |
| 27 | -2396320 |
| 28 | 4205249 |
| 29 | -7379697 |
| 30 | 12950466 |
| 31 | -22726483 |
| 32 | 39882198 |
| 33 | -69988378 |
| 34 | 122821042 |
| 35 | -215535903 |
| 36 | 378239143 |
| 37 | -663763424 |
[1,-1,2,-3,6,-10,18,-31,55,-96,169,-296,520,-912, 1601,-2809,4930,-8651,15182,-26642,46754,-82047, 143983,-252672,443409,-778128,1365520,-2396320, 4205249,-7379697,12950466,-22726483,39882198, -69988378,122821042,-215535903,378239143, -663763424] |