n | a(n) |
---|---|
1 | 0 |
2 | 0 |
3 | 0 |
4 | 1 |
5 | 4 |
6 | 13 |
7 | 41 |
8 | 130 |
9 | 415 |
10 | 1329 |
11 | 4260 |
12 | 13657 |
13 | 43781 |
14 | 140346 |
15 | 449891 |
16 | 1442157 |
17 | 4622932 |
18 | 14819125 |
19 | 47503729 |
20 | 152276498 |
21 | 488132887 |
22 | 1564743865 |
23 | 5015895108 |
24 | 16078800033 |
25 | 51541709869 |
26 | 165220529546 |
27 | 529625878779 |
28 | 1697752526549 |
[0,0,0,1,4,13,41,130,415,1329,4260,13657,43781, 140346,449891,1442157,4622932,14819125,47503729, 152276498,488132887,1564743865,5015895108, 16078800033,51541709869,165220529546,529625878779, 1697752526549] |