n | a(n) |
---|---|
0 | 1 |
1 | 0 |
2 | 6 |
3 | 18 |
4 | 90 |
5 | 192 |
6 | 864 |
7 | 1710 |
8 | 5970 |
9 | 13110 |
10 | 36810 |
11 | 75984 |
12 | 210546 |
13 | 410130 |
14 | 1003908 |
15 | 2045808 |
16 | 4616730 |
17 | 8950176 |
18 | 19746720 |
19 | 37297710 |
20 | 78247344 |
21 | 147410640 |
22 | 294299424 |
23 | 543058032 |
24 | 1067679540 |
25 | 1925323308 |
26 | 3653769792 |
27 | 6555529158 |
28 | 12129597486 |
29 | 21348640230 |
[1,0,6,18,90,192,864,1710,5970,13110,36810,75984, 210546,410130,1003908,2045808,4616730,8950176, 19746720,37297710,78247344,147410640,294299424, 543058032,1067679540,1925323308,3653769792, 6555529158,12129597486,21348640230] |