n | a(n) |
---|---|
0 | 1 |
1 | 0 |
2 | 4 |
3 | 6 |
4 | 30 |
5 | 80 |
6 | 286 |
7 | 882 |
8 | 2924 |
9 | 9350 |
10 | 30438 |
11 | 98208 |
12 | 318278 |
13 | 1029210 |
14 | 3331820 |
15 | 10780014 |
16 | 34888062 |
17 | 112894960 |
18 | 365344142 |
19 | 1182264930 |
20 | 3825911596 |
21 | 12380874550 |
22 | 40065409014 |
23 | 129654294336 |
24 | 419570260150 |
25 | 1357757640330 |
[1,0,4,6,30,80,286,882,2924,9350,30438,98208, 318278,1029210,3331820,10780014,34888062, 112894960,365344142,1182264930,3825911596, 12380874550,40065409014,129654294336,419570260150, 1357757640330] |