n | a(n) |
---|---|
0 | 1 |
1 | 9 |
2 | 50 |
3 | 220 |
4 | 840 |
5 | 2912 |
6 | 9408 |
7 | 28800 |
8 | 84480 |
9 | 239360 |
10 | 658944 |
11 | 1770496 |
12 | 4659200 |
13 | 12042240 |
14 | 30638080 |
15 | 76873728 |
16 | 190513152 |
17 | 466944000 |
18 | 1133117440 |
19 | 2724986880 |
20 | 6499598336 |
21 | 15386804224 |
22 | 36175872000 |
23 | 84515225600 |
24 | 196293427200 |
25 | 453437816832 |
[1,9,50,220,840,2912,9408,28800,84480,239360, 658944,1770496,4659200,12042240,30638080,76873728, 190513152,466944000,1133117440,2724986880, 6499598336,15386804224,36175872000,84515225600, 196293427200,453437816832] |