n | a(n) |
---|---|
1 | 0 |
2 | 2 |
3 | 4 |
4 | 13 |
5 | 62 |
6 | 222 |
7 | 820 |
8 | 3159 |
9 | 11882 |
10 | 44870 |
11 | 169628 |
12 | 640493 |
13 | 2419796 |
14 | 9141186 |
15 | 34529922 |
16 | 130440579 |
17 | 492746204 |
18 | 1861372064 |
19 | 7031443952 |
20 | 26561657355 |
21 | 100338117488 |
22 | 379032792052 |
23 | 1431817164232 |
24 | 5408768126291 |
25 | 20431919210138 |
[0,2,4,13,62,222,820,3159,11882,44870,169628, 640493,2419796,9141186,34529922,130440579, 492746204,1861372064,7031443952,26561657355, 100338117488,379032792052,1431817164232, 5408768126291,20431919210138] |