n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 0 |
3 | 1 |
4 | 2 |
5 | 6 |
6 | 17 |
7 | 57 |
8 | 191 |
9 | 663 |
10 | 2415 |
11 | 9108 |
12 | 35695 |
13 | 143989 |
14 | 599802 |
15 | 2566917 |
16 | 11298164 |
17 | 50967216 |
18 | 235745644 |
19 | 1115324000 |
20 | 5397332497 |
21 | 26669487517 |
22 | 134528555379 |
23 | 691856601631 |
24 | 3626390958551 |
25 | 19353306241764 |
26 | 105122093620388 |
27 | 580689432523534 |
28 | 3260906342453966 |
[0,0,0,1,2,6,17,57,191,663,2415,9108,35695,143989, 599802,2566917,11298164,50967216,235745644, 1115324000,5397332497,26669487517,134528555379, 691856601631,3626390958551,19353306241764, 105122093620388,580689432523534,3260906342453966] |