n | a(n) |
---|---|
0 | 1 |
1 | 0 |
2 | 1 |
3 | 0 |
4 | 9 |
5 | 24 |
6 | 225 |
7 | 504 |
8 | 16065 |
9 | 27216 |
10 | 1555281 |
11 | 6123600 |
12 | 159249321 |
13 | 779262120 |
14 | 31816914129 |
15 | 240363179784 |
16 | 8207359913025 |
17 | 66059979227424 |
18 | 2145292484152545 |
19 | 19782668403572256 |
20 | 1015331126023222281 |
21 | 7961977144683689400 |
22 | 454920488042137314561 |
[1,0,1,0,9,24,225,504,16065,27216,1555281,6123600, 159249321,779262120,31816914129,240363179784, 8207359913025,66059979227424,2145292484152545, 19782668403572256,1015331126023222281, 7961977144683689400,454920488042137314561] |