n | a(n) |
---|---|
0 | 0 |
1 | 1 |
2 | 5 |
3 | 20 |
4 | 87 |
5 | 405 |
6 | 1924 |
7 | 9225 |
8 | 44625 |
9 | 217528 |
10 | 1066725 |
11 | 5256087 |
12 | 26001000 |
13 | 129053365 |
14 | 642376709 |
15 | 3205403100 |
16 | 16029187391 |
17 | 80309053285 |
18 | 403040543420 |
19 | 2025751379997 |
20 | 10195547237235 |
21 | 51376594943136 |
22 | 259180112907875 |
23 | 1308811957775785 |
24 | 6615383878581072 |
[0,1,5,20,87,405,1924,9225,44625,217528,1066725, 5256087,26001000,129053365,642376709,3205403100, 16029187391,80309053285,403040543420, 2025751379997,10195547237235,51376594943136, 259180112907875,1308811957775785,6615383878581072] |