n | a(n) |
---|---|
1 | 0 |
2 | 6 |
3 | 30 |
4 | 198 |
5 | 1230 |
6 | 7734 |
7 | 48510 |
8 | 304422 |
9 | 1910190 |
10 | 11986326 |
11 | 75213150 |
12 | 471956358 |
13 | 2961486990 |
14 | 18583085814 |
15 | 116607324990 |
16 | 731701311462 |
17 | 4591365157230 |
18 | 28810436277846 |
19 | 180783102647070 |
20 | 1134399003458118 |
21 | 7118259838467150 |
[0,6,30,198,1230,7734,48510,304422,1910190, 11986326,75213150,471956358,2961486990, 18583085814,116607324990,731701311462, 4591365157230,28810436277846,180783102647070, 1134399003458118,7118259838467150] |