n | a(n) |
---|---|
1 | 1 |
2 | 2 |
3 | 4 |
4 | 12 |
5 | 40 |
6 | 154 |
7 | 656 |
8 | 3074 |
9 | 15616 |
10 | 85360 |
11 | 498464 |
12 | 3092450 |
13 | 20286360 |
14 | 140153382 |
15 | 1016262080 |
16 | 7710988372 |
17 | 61062381784 |
18 | 503482376930 |
19 | 4313580705728 |
20 | 38328590370762 |
21 | 352618807559008 |
22 | 3353663977088848 |
23 | 32927374589861296 |
[1,2,4,12,40,154,656,3074,15616,85360,498464, 3092450,20286360,140153382,1016262080,7710988372, 61062381784,503482376930,4313580705728, 38328590370762,352618807559008,3353663977088848, 32927374589861296] |