The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | -2 |
| 3 | 6 |
| 4 | 0 |
| 5 | 120 |
| 6 | 0 |
| 7 | 5040 |
| 8 | 0 |
| 9 | 362880 |
| 10 | 0 |
| 11 | 39916800 |
| 12 | 0 |
| 13 | 6227020800 |
| 14 | 0 |
| 15 | 1307674368000 |
| 16 | 0 |
| 17 | 355687428096000 |
| 18 | 0 |
| 19 | 121645100408832000 |
| 20 | 0 |
| 21 | 51090942171709440000 |
| 22 | 0 |
| 23 | 25852016738884976640000 |
| 24 | 0 |
| 25 | 15511210043330985984000000 |
| 26 | 0 |
| 27 | 10888869450418352160768000000 |
| 28 | 0 |
| 29 | 8841761993739701954543616000000 |
[1,1,-2,6,0,120,0,5040,0,362880,0,39916800,0, 6227020800,0,1307674368000,0,355687428096000,0, 121645100408832000,0,51090942171709440000,0, 25852016738884976640000,0, 15511210043330985984000000,0, 10888869450418352160768000000,0, 8841761993739701954543616000000] |