n | a(n) |
---|---|
1 | 2 |
2 | 20 |
3 | 126 |
4 | 728 |
5 | 4374 |
6 | 25788 |
7 | 149794 |
8 | 866692 |
9 | 4989242 |
10 | 28600208 |
11 | 163479486 |
12 | 932166044 |
13 | 5304572502 |
14 | 30137247224 |
15 | 170986774826 |
16 | 968989758580 |
17 | 5485913976922 |
18 | 31032085382272 |
19 | 175409808771550 |
20 | 990873450379996 |
[2,20,126,728,4374,25788,149794,866692,4989242, 28600208,163479486,932166044,5304572502, 30137247224,170986774826,968989758580, 5485913976922,31032085382272,175409808771550, 990873450379996] |