n | a(n) |
---|---|
0 | 0 |
1 | 1 |
2 | 2 |
3 | 6 |
4 | 20 |
5 | 70 |
6 | 252 |
7 | 924 |
8 | 3432 |
9 | 12870 |
10 | 48620 |
11 | 183755 |
12 | 683046 |
13 | 2443168 |
14 | 8263360 |
15 | 26184420 |
16 | 77558760 |
17 | 215182923 |
18 | 561542454 |
19 | 1385168400 |
20 | 3245959640 |
21 | 7260395142 |
22 | 15567955260 |
23 | 32124894880 |
24 | 64016082000 |
25 | 123566718600 |
26 | 231661933776 |
27 | 422854091037 |
28 | 753068219386 |
[0,1,2,6,20,70,252,924,3432,12870,48620,183755, 683046,2443168,8263360,26184420,77558760, 215182923,561542454,1385168400,3245959640, 7260395142,15567955260,32124894880,64016082000, 123566718600,231661933776,422854091037, 753068219386] |