n | a(n) |
---|---|
1 | 1 |
2 | -2 |
3 | 4 |
4 | -10 |
5 | 30 |
6 | -104 |
7 | 392 |
8 | -1568 |
9 | 6520 |
10 | -27976 |
11 | 122944 |
12 | -551680 |
13 | 2518912 |
14 | -11684000 |
15 | 54957216 |
16 | -261897024 |
17 | 1263216192 |
18 | -6164172608 |
19 | 30416619200 |
20 | -151750104800 |
21 | 765364073120 |
22 | -3902783995520 |
23 | 20123276097920 |
[1,-2,4,-10,30,-104,392,-1568,6520,-27976,122944, -551680,2518912,-11684000,54957216,-261897024, 1263216192,-6164172608,30416619200,-151750104800, 765364073120,-3902783995520,20123276097920] |