n | a(n) |
---|---|
0 | 0 |
1 | 1 |
2 | 4 |
3 | 15 |
4 | 52 |
5 | 185 |
6 | 648 |
7 | 2287 |
8 | 8040 |
9 | 28321 |
10 | 99660 |
11 | 350879 |
12 | 1235036 |
13 | 4347705 |
14 | 15304208 |
15 | 53873695 |
16 | 189642192 |
17 | 667570433 |
18 | 2349942420 |
19 | 8272149359 |
20 | 29119170180 |
21 | 102503781241 |
22 | 360828342424 |
23 | 1270168882575 |
24 | 4471181087032 |
25 | 15739215003425 |
[0,1,4,15,52,185,648,2287,8040,28321,99660,350879, 1235036,4347705,15304208,53873695,189642192, 667570433,2349942420,8272149359,29119170180, 102503781241,360828342424,1270168882575, 4471181087032,15739215003425] |