n | a(n) |
---|---|
2 | 2 |
3 | 18 |
4 | 84 |
5 | 300 |
6 | 930 |
7 | 2646 |
8 | 7112 |
9 | 18360 |
10 | 45990 |
11 | 112530 |
12 | 270204 |
13 | 638820 |
14 | 1490762 |
15 | 3440430 |
16 | 7864080 |
17 | 17825520 |
18 | 40107726 |
19 | 89652906 |
20 | 199229060 |
21 | 440401500 |
22 | 968883762 |
23 | 2122317318 |
24 | 4630511064 |
25 | 10066329000 |
26 | 21810380150 |
27 | 47110421826 |
28 | 101468601612 |
29 | 217969589460 |
30 | 467077692570 |
[2,18,84,300,930,2646,7112,18360,45990,112530, 270204,638820,1490762,3440430,7864080,17825520, 40107726,89652906,199229060,440401500,968883762, 2122317318,4630511064,10066329000,21810380150, 47110421826,101468601612,217969589460, 467077692570] |