n | a(n) |
---|---|
1 | 0 |
2 | 0 |
3 | 6 |
4 | 40 |
5 | 186 |
6 | 816 |
7 | 3396 |
8 | 14040 |
9 | 57306 |
10 | 233000 |
11 | 943608 |
12 | 3813000 |
13 | 15378716 |
14 | 61946640 |
15 | 249260316 |
16 | 1002158880 |
17 | 4026527706 |
18 | 16169288640 |
19 | 64901712996 |
20 | 260410648680 |
21 | 1044535993800 |
22 | 4188615723280 |
23 | 16792541033556 |
24 | 67309233561240 |
25 | 269746851976156 |
[0,0,6,40,186,816,3396,14040,57306,233000,943608, 3813000,15378716,61946640,249260316,1002158880, 4026527706,16169288640,64901712996,260410648680, 1044535993800,4188615723280,16792541033556, 67309233561240,269746851976156] |