n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 0 |
3 | 0 |
4 | 2 |
5 | 10 |
6 | 44 |
7 | 179 |
8 | 702 |
9 | 2701 |
10 | 10278 |
11 | 38866 |
12 | 146450 |
13 | 550817 |
14 | 2070116 |
15 | 7779655 |
16 | 29248932 |
17 | 110047905 |
18 | 414446256 |
19 | 1562538171 |
20 | 5898049688 |
21 | 22290789562 |
22 | 84351810044 |
23 | 319609669957 |
24 | 1212552963576 |
25 | 4606078246284 |
26 | 17518748817596 |
27 | 66712192842068 |
28 | 254346235738120 |
[0,0,0,0,2,10,44,179,702,2701,10278,38866,146450, 550817,2070116,7779655,29248932,110047905, 414446256,1562538171,5898049688,22290789562, 84351810044,319609669957,1212552963576, 4606078246284,17518748817596,66712192842068, 254346235738120] |