n | a(n) |
---|---|
0 | 1 |
1 | -1 |
2 | 4 |
3 | 20 |
4 | 56 |
5 | 120 |
6 | 560 |
7 | 4960 |
8 | 19600 |
9 | 41664 |
10 | 341376 |
11 | 695520 |
12 | 7207200 |
13 | 22238720 |
14 | 178433024 |
15 | 1429559296 |
16 | 179481600 |
17 | 11453245440 |
18 | 11444858880 |
19 | 393079864320 |
20 | 3928874471424 |
21 | 5864598896640 |
22 | 46910348656640 |
23 | 975649558118400 |
24 | 3002365391929344 |
25 | 7805131503206400 |
[1,-1,4,20,56,120,560,4960,19600,41664,341376, 695520,7207200,22238720,178433024,1429559296, 179481600,11453245440,11444858880,393079864320, 3928874471424,5864598896640,46910348656640, 975649558118400,3002365391929344,7805131503206400] |