n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 0 |
3 | 4 |
4 | 20 |
5 | 80 |
6 | 288 |
7 | 976 |
8 | 3184 |
9 | 10112 |
10 | 31488 |
11 | 96576 |
12 | 292672 |
13 | 878336 |
14 | 2614784 |
15 | 7731456 |
16 | 22728448 |
17 | 66482176 |
18 | 193617920 |
19 | 561718272 |
20 | 1624101888 |
21 | 4681535488 |
22 | 13457924096 |
23 | 38592008192 |
24 | 110419341312 |
25 | 315287830528 |
26 | 898583560192 |
[0,0,0,4,20,80,288,976,3184,10112,31488,96576, 292672,878336,2614784,7731456,22728448,66482176, 193617920,561718272,1624101888,4681535488, 13457924096,38592008192,110419341312,315287830528, 898583560192] |