n | a(n) |
---|---|
1 | 1 |
2 | 2 |
3 | 6 |
4 | 20 |
5 | 87 |
6 | 420 |
7 | 2254 |
8 | 12676 |
9 | 73819 |
10 | 438795 |
11 | 2649555 |
12 | 16188915 |
13 | 99888892 |
14 | 621428188 |
15 | 3893646748 |
16 | 24548337096 |
17 | 155622071065 |
18 | 991375878185 |
19 | 6343073841027 |
[1,2,6,20,87,420,2254,12676,73819,438795,2649555, 16188915,99888892,621428188,3893646748, 24548337096,155622071065,991375878185, 6343073841027] |