n | a(n) |
---|---|
1 | 0 |
2 | 0 |
3 | 0 |
4 | 0 |
5 | 1 |
6 | 4 |
7 | 19 |
8 | 93 |
9 | 539 |
10 | 3474 |
11 | 24856 |
12 | 192972 |
13 | 1613219 |
14 | 14410374 |
15 | 136920388 |
16 | 1378542639 |
17 | 14663082556 |
18 | 164340455701 |
19 | 1936286904952 |
20 | 23932267735948 |
21 | 309701296575063 |
[0,0,0,0,1,4,19,93,539,3474,24856,192972,1613219, 14410374,136920388,1378542639,14663082556, 164340455701,1936286904952,23932267735948, 309701296575063] |