n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 4 |
3 | 40 |
4 | 664 |
5 | 15424 |
6 | 460576 |
7 | 16808320 |
8 | 724904896 |
9 | 36072438016 |
10 | 2034328297984 |
11 | 128223244372480 |
12 | 8932539799788544 |
13 | 681536817951791104 |
14 | 56521548341146402816 |
15 | 5062454448656689500160 |
16 | 487013865350356256137216 |
17 | 50082306316236214342844416 |
18 | 5482502331779770770018893824 |
[1,1,4,40,664,15424,460576,16808320,724904896, 36072438016,2034328297984,128223244372480, 8932539799788544,681536817951791104, 56521548341146402816,5062454448656689500160, 487013865350356256137216, 50082306316236214342844416, 5482502331779770770018893824] |