n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 0 |
3 | 1 |
4 | 2 |
5 | 4 |
6 | 9 |
7 | 23 |
8 | 61 |
9 | 168 |
10 | 469 |
11 | 1326 |
12 | 3776 |
13 | 10833 |
14 | 31228 |
15 | 90438 |
16 | 262860 |
17 | 766497 |
18 | 2241194 |
19 | 6569206 |
20 | 19296214 |
21 | 56789286 |
22 | 167419568 |
23 | 494337282 |
24 | 1461690270 |
25 | 4327638394 |
26 | 12828158828 |
27 | 38067670764 |
28 | 113081627856 |
29 | 336233591365 |
30 | 1000636296475 |
31 | 2980391776958 |
[0,0,0,1,2,4,9,23,61,168,469,1326,3776,10833, 31228,90438,262860,766497,2241194,6569206, 19296214,56789286,167419568,494337282,1461690270, 4327638394,12828158828,38067670764,113081627856, 336233591365,1000636296475,2980391776958] |