n | a(n) |
---|---|
0 | 1 |
1 | 5 |
2 | 20 |
3 | 68 |
4 | 268 |
5 | 1020 |
6 | 4236 |
7 | 17020 |
8 | 67220 |
9 | 269180 |
10 | 1076084 |
11 | 4298556 |
12 | 17141436 |
13 | 68333836 |
14 | 272489556 |
15 | 1087119500 |
[1,5,20,68,268,1020,4236,17020,67220,269180, 1076084,4298556,17141436,68333836,272489556, 1087119500] |