n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 0 |
3 | 4 |
4 | 18 |
5 | 100 |
6 | 448 |
7 | 2028 |
8 | 8820 |
9 | 38148 |
10 | 163350 |
11 | 697048 |
12 | 2965248 |
13 | 12595048 |
14 | 53440504 |
15 | 226608900 |
16 | 960530634 |
17 | 4070452764 |
18 | 17246835648 |
19 | 73069580980 |
20 | 309555981900 |
21 | 1311374255620 |
22 | 5555264316910 |
23 | 23532984885744 |
24 | 99688652356608 |
25 | 422291386890000 |
[0,0,0,4,18,100,448,2028,8820,38148,163350,697048, 2965248,12595048,53440504,226608900,960530634, 4070452764,17246835648,73069580980,309555981900, 1311374255620,5555264316910,23532984885744, 99688652356608,422291386890000] |