n | a(n) |
---|---|
0 | 1 |
1 | 2 |
2 | 6 |
3 | 16 |
4 | 48 |
5 | 140 |
6 | 420 |
7 | 1248 |
8 | 3744 |
9 | 11200 |
10 | 33600 |
11 | 100704 |
12 | 302112 |
13 | 906056 |
14 | 2718168 |
15 | 8153664 |
16 | 24460992 |
17 | 73380480 |
18 | 220141440 |
19 | 660416832 |
20 | 1981250496 |
21 | 5943729088 |
22 | 17831187264 |
23 | 53493494592 |
24 | 160480483776 |
25 | 481441249920 |
26 | 1444323749760 |
[1,2,6,16,48,140,420,1248,3744,11200,33600,100704, 302112,906056,2718168,8153664,24460992,73380480, 220141440,660416832,1981250496,5943729088, 17831187264,53493494592,160480483776,481441249920, 1444323749760] |