n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 2 |
3 | 6 |
4 | 15 |
5 | 45 |
6 | 136 |
7 | 430 |
8 | 1415 |
9 | 4845 |
10 | 17235 |
11 | 63508 |
12 | 242841 |
13 | 959746 |
14 | 3924747 |
15 | 16551199 |
16 | 71994097 |
17 | 322098625 |
18 | 1481655067 |
19 | 6990945197 |
20 | 33812067833 |
21 | 167294687170 |
22 | 846131720816 |
23 | 4367249636291 |
24 | 22985935628080 |
25 | 123193976095986 |
26 | 671862417595209 |
27 | 3724122166971836 |
[1,1,2,6,15,45,136,430,1415,4845,17235,63508, 242841,959746,3924747,16551199,71994097,322098625, 1481655067,6990945197,33812067833,167294687170, 846131720816,4367249636291,22985935628080, 123193976095986,671862417595209,3724122166971836] |