The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 5 |
| 4 | -4 |
| 5 | 18 |
| 6 | -20 |
| 7 | 47 |
| 8 | -56 |
| 9 | 110 |
| 10 | -153 |
| 11 | 309 |
| 12 | -532 |
| 13 | 1045 |
| 14 | -1768 |
| 15 | 2855 |
| 16 | -3620 |
| 17 | 2928 |
| 18 | 2927 |
| 19 | -20371 |
| 20 | 62261 |
| 21 | -148774 |
| 22 | 314112 |
| 23 | -613835 |
| 24 | 1155936 |
| 25 | -2175658 |
| 26 | 4244218 |
| 27 | -8753316 |
| 28 | 19006746 |
| 29 | -42471491 |
| 30 | 95234915 |
| 31 | -210395017 |
| 32 | 453414314 |
| 33 | -949507878 |
| 34 | 1931940045 |
[1,1,1,5,-4,18,-20,47,-56,110,-153,309,-532,1045, -1768,2855,-3620,2928,2927,-20371,62261,-148774, 314112,-613835,1155936,-2175658,4244218,-8753316, 19006746,-42471491,95234915,-210395017,453414314, -949507878,1931940045] |