n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 0 |
3 | 2 |
4 | 8 |
5 | 20 |
6 | 80 |
7 | 350 |
8 | 1232 |
9 | 5768 |
10 | 31040 |
11 | 142010 |
12 | 776600 |
13 | 4874012 |
14 | 27027728 |
15 | 168369110 |
16 | 1191911840 |
17 | 7678566800 |
18 | 53474964992 |
19 | 418199988338 |
20 | 3044269834280 |
21 | 23364756531620 |
22 | 199008751634000 |
23 | 1605461415071822 |
[0,0,0,2,8,20,80,350,1232,5768,31040,142010, 776600,4874012,27027728,168369110,1191911840, 7678566800,53474964992,418199988338,3044269834280, 23364756531620,199008751634000,1605461415071822] |