n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 6 |
3 | 30 |
4 | 140 |
5 | 560 |
6 | 2058 |
7 | 7098 |
8 | 23472 |
9 | 75372 |
10 | 237182 |
11 | 735878 |
12 | 2260596 |
13 | 6896136 |
14 | 20933778 |
15 | 63325170 |
16 | 191089112 |
17 | 575626052 |
18 | 1731858246 |
19 | 5206059774 |
20 | 15640198620 |
21 | 46966732320 |
22 | 140996664986 |
23 | 423191320490 |
24 | 1269993390720 |
[0,0,6,30,140,560,2058,7098,23472,75372,237182, 735878,2260596,6896136,20933778,63325170, 191089112,575626052,1731858246,5206059774, 15640198620,46966732320,140996664986,423191320490, 1269993390720] |