n | a(n) |
---|---|
1 | 0 |
2 | 1 |
3 | 5 |
4 | 25 |
5 | 147 |
6 | 996 |
7 | 7668 |
8 | 66264 |
9 | 635976 |
10 | 6717600 |
11 | 77482080 |
12 | 969338880 |
13 | 13076778240 |
14 | 189261999360 |
15 | 2925629280000 |
16 | 48111515827200 |
17 | 838731380659200 |
18 | 15451544605593600 |
19 | 299960798422118400 |
20 | 6120505381423104000 |
[0,1,5,25,147,996,7668,66264,635976,6717600, 77482080,969338880,13076778240,189261999360, 2925629280000,48111515827200,838731380659200, 15451544605593600,299960798422118400, 6120505381423104000] |