n | a(n) |
---|---|
0 | 1 |
1 | 4 |
2 | 12 |
3 | 42 |
4 | 148 |
5 | 540 |
6 | 1990 |
7 | 7434 |
8 | 27972 |
9 | 106008 |
10 | 403764 |
11 | 1544796 |
12 | 5931486 |
13 | 22846252 |
14 | 88228998 |
15 | 341518606 |
16 | 1324627044 |
17 | 5146959168 |
18 | 20030812360 |
19 | 78066774400 |
20 | 304643526276 |
21 | 1190209498344 |
22 | 4654949367204 |
23 | 18223301727108 |
[1,4,12,42,148,540,1990,7434,27972,106008,403764, 1544796,5931486,22846252,88228998,341518606, 1324627044,5146959168,20030812360,78066774400, 304643526276,1190209498344,4654949367204, 18223301727108] |