n | a(n) |
---|---|
0 | 0 |
1 | 2 |
2 | -1 |
3 | 12 |
4 | -30 |
5 | 270 |
6 | -1215 |
7 | 12600 |
8 | -81900 |
9 | 992250 |
10 | -8434125 |
11 | 117879300 |
12 | -1237732650 |
13 | 19666196550 |
14 | -245827456875 |
15 | 4382752374000 |
16 | -63549909423000 |
17 | 1257302087291250 |
18 | -20745484440305625 |
19 | 451231749105637500 |
[0,2,-1,12,-30,270,-1215,12600,-81900,992250, -8434125,117879300,-1237732650,19666196550, -245827456875,4382752374000,-63549909423000, 1257302087291250,-20745484440305625, 451231749105637500] |