n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 2 |
3 | 16 |
4 | 118 |
5 | 926 |
6 | 7956 |
7 | 75132 |
8 | 777456 |
9 | 8771184 |
10 | 107307360 |
11 | 1416252960 |
12 | 20068629120 |
13 | 304002322560 |
14 | 4903642679040 |
15 | 83928856838400 |
16 | 1519397749094400 |
17 | 29010025797580800 |
18 | 582647327132774400 |
19 | 12280347845905305600 |
20 | 271030782903552000000 |
21 | 6251213902855219200000 |
[0,0,2,16,118,926,7956,75132,777456,8771184, 107307360,1416252960,20068629120,304002322560, 4903642679040,83928856838400,1519397749094400, 29010025797580800,582647327132774400, 12280347845905305600,271030782903552000000, 6251213902855219200000] |