n | a(n) |
---|---|
3 | 1 |
4 | 4 |
5 | 13 |
6 | 28 |
7 | 70 |
8 | 418 |
9 | 3187 |
10 | 20380 |
11 | 144781 |
12 | 1561781 |
13 | 23475489 |
14 | 388651137 |
15 | 7313541265 |
16 | 177385458253 |
17 | 5624711721417 |
18 | 217536953984714 |
[1,4,13,28,70,418,3187,20380,144781,1561781, 23475489,388651137,7313541265,177385458253, 5624711721417,217536953984714] |