n | a(n) |
---|---|
0 | 1 |
1 | 4 |
2 | 22 |
3 | 132 |
4 | 729 |
5 | 4000 |
6 | 21488 |
7 | 113760 |
8 | 594548 |
9 | 3073392 |
10 | 15732936 |
11 | 79846448 |
12 | 402104884 |
13 | 2010879968 |
14 | 9992425872 |
15 | 49366096352 |
16 | 242584319710 |
17 | 1186177166680 |
18 | 5773569726884 |
19 | 27982357252632 |
20 | 135079969593838 |
21 | 649640609539360 |
22 | 3113354757088720 |
23 | 14871179093155424 |
[1,4,22,132,729,4000,21488,113760,594548,3073392, 15732936,79846448,402104884,2010879968,9992425872, 49366096352,242584319710,1186177166680, 5773569726884,27982357252632,135079969593838, 649640609539360,3113354757088720, 14871179093155424] |