n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 0 |
3 | 0 |
4 | 2 |
5 | 6 |
6 | 25 |
7 | 88 |
8 | 335 |
9 | 1215 |
10 | 4534 |
11 | 16823 |
12 | 63159 |
13 | 237679 |
14 | 900341 |
15 | 3423201 |
16 | 13073163 |
17 | 50095285 |
18 | 192599091 |
19 | 742576616 |
20 | 2870584814 |
21 | 11122879867 |
22 | 43191525139 |
23 | 168046317330 |
24 | 654998425237 |
25 | 2557224396342 |
26 | 9999083912711 |
27 | 39153000738695 |
28 | 153511081627903 |
[0,0,0,0,2,6,25,88,335,1215,4534,16823,63159, 237679,900341,3423201,13073163,50095285,192599091, 742576616,2870584814,11122879867,43191525139, 168046317330,654998425237,2557224396342, 9999083912711,39153000738695,153511081627903] |