n | a(n) |
---|---|
0 | 1 |
1 | 2 |
2 | 6 |
3 | 20 |
4 | 64 |
5 | 206 |
6 | 662 |
7 | 2128 |
8 | 6840 |
9 | 21986 |
10 | 70670 |
11 | 227156 |
12 | 730152 |
13 | 2346942 |
14 | 7543822 |
15 | 24248256 |
16 | 77941648 |
17 | 250529378 |
18 | 805281526 |
19 | 2588432308 |
20 | 8320049072 |
21 | 26743297998 |
22 | 85961510758 |
23 | 276307781200 |
24 | 888141556360 |
25 | 2854770939522 |
[1,2,6,20,64,206,662,2128,6840,21986,70670,227156, 730152,2346942,7543822,24248256,77941648, 250529378,805281526,2588432308,8320049072, 26743297998,85961510758,276307781200,888141556360, 2854770939522] |