n | a(n) |
---|---|
0 | 1 |
1 | 6 |
2 | 15 |
3 | 70 |
4 | 315 |
5 | 1554 |
6 | 7735 |
7 | 39990 |
8 | 209790 |
9 | 1119720 |
10 | 6045837 |
11 | 32981550 |
12 | 181394535 |
13 | 1004668770 |
14 | 5597420295 |
15 | 31345665106 |
16 | 176319264240 |
17 | 995685849690 |
18 | 5642219252460 |
19 | 32071565263710 |
20 | 182807918979777 |
[1,6,15,70,315,1554,7735,39990,209790,1119720, 6045837,32981550,181394535,1004668770,5597420295, 31345665106,176319264240,995685849690, 5642219252460,32071565263710,182807918979777] |