n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 1 |
3 | 2 |
4 | 6 |
5 | 16 |
6 | 42 |
7 | 110 |
8 | 289 |
9 | 756 |
10 | 1980 |
11 | 5184 |
12 | 13572 |
13 | 35532 |
14 | 93025 |
15 | 243542 |
16 | 637602 |
17 | 1669264 |
18 | 4370190 |
19 | 11441306 |
20 | 29953729 |
21 | 78419880 |
22 | 205305912 |
23 | 537497856 |
24 | 1407187656 |
25 | 3684065112 |
26 | 9645007681 |
27 | 25250957930 |
28 | 66107866110 |
[0,0,1,2,6,16,42,110,289,756,1980,5184,13572, 35532,93025,243542,637602,1669264,4370190, 11441306,29953729,78419880,205305912,537497856, 1407187656,3684065112,9645007681,25250957930, 66107866110] |