n | a(n) |
---|---|
2 | 1 |
3 | 5 |
4 | 20 |
5 | 75 |
6 | 275 |
7 | 1001 |
8 | 3640 |
9 | 13260 |
10 | 48450 |
11 | 177650 |
12 | 653752 |
13 | 2414425 |
14 | 8947575 |
15 | 33266625 |
16 | 124062000 |
17 | 463991880 |
18 | 1739969550 |
19 | 6541168950 |
20 | 24647883000 |
21 | 93078189750 |
22 | 352207870014 |
23 | 1335293573130 |
24 | 5071418015120 |
25 | 19293438101000 |
26 | 73514652074500 |
27 | 280531912316292 |
[1,5,20,75,275,1001,3640,13260,48450,177650, 653752,2414425,8947575,33266625,124062000, 463991880,1739969550,6541168950,24647883000, 93078189750,352207870014,1335293573130, 5071418015120,19293438101000,73514652074500, 280531912316292] |