n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 0 |
3 | 6 |
4 | 30 |
5 | 114 |
6 | 402 |
7 | 1386 |
8 | 4746 |
9 | 16218 |
10 | 55386 |
11 | 189114 |
12 | 645690 |
13 | 2204538 |
14 | 7526778 |
15 | 25698042 |
16 | 87738618 |
17 | 299558394 |
18 | 1022756346 |
19 | 3491908602 |
20 | 11922121722 |
21 | 40704669690 |
22 | 138974435322 |
23 | 474488401914 |
24 | 1620004737018 |
25 | 5531042144250 |
26 | 18884159102970 |
27 | 64474552123386 |
[0,0,0,6,30,114,402,1386,4746,16218,55386,189114, 645690,2204538,7526778,25698042,87738618, 299558394,1022756346,3491908602,11922121722, 40704669690,138974435322,474488401914, 1620004737018,5531042144250,18884159102970, 64474552123386] |