n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 4 |
3 | 18 |
4 | 96 |
5 | 374 |
6 | 1380 |
7 | 4696 |
8 | 15336 |
9 | 48318 |
10 | 148448 |
11 | 446890 |
12 | 1324104 |
13 | 3872656 |
14 | 11206764 |
15 | 32143818 |
16 | 91509120 |
17 | 258855006 |
18 | 728211180 |
19 | 2038815272 |
20 | 5684262480 |
21 | 15789141750 |
22 | 43712852544 |
23 | 120663667538 |
24 | 332191809936 |
25 | 912339490464 |
[0,0,4,18,96,374,1380,4696,15336,48318,148448, 446890,1324104,3872656,11206764,32143818,91509120, 258855006,728211180,2038815272,5684262480, 15789141750,43712852544,120663667538,332191809936, 912339490464] |