n | a(n) |
---|---|
1 | -1 |
2 | 1 |
3 | -7 |
4 | 24 |
5 | -121 |
6 | 720 |
7 | -5040 |
8 | 40319 |
9 | -362880 |
10 | 3628800 |
11 | -39916801 |
12 | 479001600 |
13 | -6227020801 |
14 | 87178291199 |
15 | -1307674368000 |
16 | 20922789887999 |
17 | -355687428096000 |
18 | 6402373705728000 |
19 | -121645100408832001 |
20 | 2432902008176640000 |
[-1,1,-7,24,-121,720,-5040,40319,-362880,3628800, -39916801,479001600,-6227020801,87178291199, -1307674368000,20922789887999,-355687428096000, 6402373705728000,-121645100408832001, 2432902008176640000] |