n | a(n) |
---|---|
1 | 0 |
2 | 0 |
3 | 0 |
4 | 1 |
5 | 5 |
6 | 20 |
7 | 75 |
8 | 271 |
9 | 957 |
10 | 3337 |
11 | 11559 |
12 | 39896 |
13 | 137423 |
14 | 472808 |
15 | 1625632 |
16 | 5587228 |
17 | 19198971 |
18 | 65963978 |
19 | 226623902 |
20 | 778551761 |
21 | 2674604282 |
22 | 9188106871 |
23 | 31563807424 |
24 | 108430368827 |
25 | 372487292867 |
26 | 1279591674070 |
27 | 4395730089428 |
[0,0,0,1,5,20,75,271,957,3337,11559,39896,137423, 472808,1625632,5587228,19198971,65963978, 226623902,778551761,2674604282,9188106871, 31563807424,108430368827,372487292867, 1279591674070,4395730089428] |