n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 0 |
3 | 2 |
4 | 6 |
5 | 18 |
6 | 56 |
7 | 162 |
8 | 462 |
9 | 1306 |
10 | 3648 |
11 | 10116 |
12 | 27892 |
13 | 76524 |
14 | 209112 |
15 | 569506 |
16 | 1546542 |
17 | 4189314 |
18 | 11323480 |
19 | 30548190 |
20 | 82272330 |
21 | 221240070 |
22 | 594131160 |
23 | 1593553452 |
24 | 4269391596 |
25 | 11426761548 |
26 | 30554523096 |
27 | 81631135502 |
28 | 217918012002 |
[0,0,0,2,6,18,56,162,462,1306,3648,10116,27892, 76524,209112,569506,1546542,4189314,11323480, 30548190,82272330,221240070,594131160,1593553452, 4269391596,11426761548,30554523096,81631135502, 217918012002] |