The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | -3 |
| 4 | -15 |
| 5 | 5 |
| 6 | 345 |
| 7 | 889 |
| 8 | -11263 |
| 9 | -82167 |
| 10 | 455025 |
| 11 | 7869301 |
| 12 | -16466703 |
| 13 | -906141171 |
| 14 | -746021367 |
| 15 | 128450716913 |
| 16 | 480286325633 |
| 17 | -22562588189167 |
| 18 | -150637957014303 |
| 19 | 4955964959446253 |
| 20 | 46203820378253425 |
[1,1,1,-3,-15,5,345,889,-11263,-82167,455025, 7869301,-16466703,-906141171,-746021367, 128450716913,480286325633,-22562588189167, -150637957014303,4955964959446253, 46203820378253425] |