n | a(n) |
---|---|
1 | 1 |
2 | -1 |
3 | 0 |
4 | 6 |
5 | -24 |
6 | 0 |
7 | 720 |
8 | -5040 |
9 | 0 |
10 | 362880 |
11 | -3628800 |
12 | 0 |
13 | 479001600 |
14 | -6227020800 |
15 | 0 |
16 | 1307674368000 |
17 | -20922789888000 |
18 | 0 |
19 | 6402373705728000 |
20 | -121645100408832000 |
21 | 0 |
22 | 51090942171709440000 |
23 | -1124000727777607680000 |
[1,-1,0,6,-24,0,720,-5040,0,362880,-3628800,0, 479001600,-6227020800,0,1307674368000, -20922789888000,0,6402373705728000, -121645100408832000,0,51090942171709440000, -1124000727777607680000] |