The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | -16 |
| 2 | 120 |
| 3 | -576 |
| 4 | 2076 |
| 5 | -6304 |
| 6 | 17344 |
| 7 | -44416 |
| 8 | 106630 |
| 9 | -242480 |
| 10 | 528608 |
| 11 | -1112128 |
| 12 | 2265656 |
| 13 | -4486112 |
| 14 | 8666112 |
| 15 | -16376192 |
| 16 | 30328593 |
| 17 | -55145872 |
| 18 | 98613424 |
| 19 | -173670400 |
| 20 | 301550788 |
| 21 | -516747872 |
| 22 | 874774016 |
| 23 | -1464096000 |
[1,-16,120,-576,2076,-6304,17344,-44416,106630, -242480,528608,-1112128,2265656,-4486112,8666112, -16376192,30328593,-55145872,98613424,-173670400, 301550788,-516747872,874774016,-1464096000] |