n | a(n) |
---|---|
4 | 1 |
5 | 0 |
6 | 2 |
7 | 4 |
8 | 12 |
9 | 32 |
10 | 110 |
11 | 340 |
12 | 1209 |
13 | 4272 |
14 | 16166 |
15 | 61848 |
16 | 246660 |
17 | 1004883 |
18 | 4209124 |
19 | 18020832 |
20 | 78898047 |
21 | 352437205 |
22 | 1605225878 |
23 | 7445515638 |
24 | 35142033027 |
25 | 168644213617 |
26 | 822311934788 |
27 | 4071431204506 |
28 | 20457850555113 |
[1,0,2,4,12,32,110,340,1209,4272,16166,61848, 246660,1004883,4209124,18020832,78898047, 352437205,1605225878,7445515638,35142033027, 168644213617,822311934788,4071431204506, 20457850555113] |