n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 3 |
3 | 6 |
4 | 20 |
5 | 50 |
6 | 175 |
7 | 490 |
8 | 1764 |
9 | 5292 |
10 | 19404 |
11 | 60984 |
12 | 226512 |
13 | 736164 |
14 | 2760615 |
15 | 9202050 |
16 | 34763300 |
17 | 118195220 |
18 | 449141836 |
19 | 1551580888 |
20 | 5924217936 |
21 | 20734762776 |
22 | 79483257308 |
23 | 281248448936 |
24 | 1081724803600 |
25 | 3863302870000 |
26 | 14901311070000 |
27 | 53644719852000 |
[1,1,3,6,20,50,175,490,1764,5292,19404,60984, 226512,736164,2760615,9202050,34763300,118195220, 449141836,1551580888,5924217936,20734762776, 79483257308,281248448936,1081724803600, 3863302870000,14901311070000,53644719852000] |