n | a(n) |
---|---|
2 | 1 |
3 | 3 |
4 | 15 |
5 | 45 |
6 | 189 |
7 | 588 |
8 | 2352 |
9 | 7560 |
10 | 29700 |
11 | 98010 |
12 | 382239 |
13 | 1288287 |
14 | 5010005 |
15 | 17177160 |
16 | 66745536 |
17 | 232092432 |
18 | 901995588 |
19 | 3173688180 |
20 | 12342120700 |
21 | 43861998180 |
22 | 170724392916 |
23 | 611947174608 |
24 | 2384209771200 |
25 | 8609646396000 |
26 | 33577620944400 |
27 | 122041737663300 |
28 | 476432168185575 |
[1,3,15,45,189,588,2352,7560,29700,98010,382239, 1288287,5010005,17177160,66745536,232092432, 901995588,3173688180,12342120700,43861998180, 170724392916,611947174608,2384209771200, 8609646396000,33577620944400,122041737663300, 476432168185575] |