n | a(n) |
---|---|
1 | 1 |
2 | 0 |
3 | 1 |
4 | 4 |
5 | 14 |
6 | 46 |
7 | 148 |
8 | 474 |
9 | 1518 |
10 | 4864 |
11 | 15590 |
12 | 49974 |
13 | 160196 |
14 | 513522 |
15 | 1646134 |
16 | 5276800 |
17 | 16915150 |
18 | 54222686 |
19 | 173814580 |
20 | 557174698 |
21 | 1786062174 |
22 | 5725346304 |
23 | 18352995094 |
24 | 58831800038 |
25 | 188589419748 |
26 | 604536478850 |
27 | 1937883656166 |
[1,0,1,4,14,46,148,474,1518,4864,15590,49974, 160196,513522,1646134,5276800,16915150,54222686, 173814580,557174698,1786062174,5725346304, 18352995094,58831800038,188589419748,604536478850, 1937883656166] |