n | a(n) |
---|---|
1 | 0 |
2 | 2 |
3 | 2 |
4 | 6 |
5 | 14 |
6 | 39 |
7 | 125 |
8 | 399 |
9 | 1310 |
10 | 4356 |
11 | 14970 |
12 | 51715 |
13 | 178832 |
14 | 635778 |
15 | 2290019 |
16 | 8106059 |
17 | 29234378 |
18 | 105635076 |
19 | 384409483 |
20 | 1408730050 |
21 | 5193316109 |
22 | 19170300330 |
23 | 71421970661 |
24 | 263893092145 |
25 | 984568438169 |
26 | 3686368605467 |
27 | 13838552783467 |
28 | 52008816746450 |
[0,2,2,6,14,39,125,399,1310,4356,14970,51715, 178832,635778,2290019,8106059,29234378,105635076, 384409483,1408730050,5193316109,19170300330, 71421970661,263893092145,984568438169, 3686368605467,13838552783467,52008816746450] |