n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 1 |
3 | 3 |
4 | 9 |
5 | 45 |
6 | 225 |
7 | 1575 |
8 | 11024 |
9 | 99216 |
10 | 891984 |
11 | 9811824 |
12 | 107544862 |
13 | 1398083206 |
14 | 18043262766 |
15 | 270648941490 |
16 | 4013029762464 |
17 | 68221505961888 |
18 | 1141412702224688 |
19 | 21686841342269072 |
20 | 403841897925538896 |
21 | 8480679856436316816 |
22 | 173881330973591388704 |
[1,1,1,3,9,45,225,1575,11024,99216,891984,9811824, 107544862,1398083206,18043262766,270648941490, 4013029762464,68221505961888,1141412702224688, 21686841342269072,403841897925538896, 8480679856436316816,173881330973591388704] |