n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 1 |
3 | 5 |
4 | 17 |
5 | 52 |
6 | 156 |
7 | 468 |
8 | 1405 |
9 | 4217 |
10 | 12653 |
11 | 37960 |
12 | 113880 |
13 | 341640 |
14 | 1024921 |
15 | 3074765 |
16 | 9224297 |
17 | 27672892 |
18 | 83018676 |
19 | 249056028 |
20 | 747168085 |
21 | 2241504257 |
22 | 6724512773 |
23 | 20173538320 |
24 | 60520614960 |
25 | 181561844880 |
[0,0,1,5,17,52,156,468,1405,4217,12653,37960, 113880,341640,1024921,3074765,9224297,27672892, 83018676,249056028,747168085,2241504257, 6724512773,20173538320,60520614960,181561844880] |