n | a(n) |
---|---|
0 | 1 |
1 | 3 |
2 | 9 |
3 | 28 |
4 | 90 |
5 | 300 |
6 | 1051 |
7 | 3975 |
8 | 16971 |
9 | 86584 |
10 | 550560 |
11 | 4354308 |
12 | 41245021 |
13 | 448722207 |
14 | 5443128597 |
15 | 72294557416 |
16 | 1039558994214 |
17 | 16059538853232 |
18 | 264996063891607 |
19 | 4648786414414347 |
20 | 86363450200625247 |
21 | 1693336666564186012 |
[1,3,9,28,90,300,1051,3975,16971,86584,550560, 4354308,41245021,448722207,5443128597,72294557416, 1039558994214,16059538853232,264996063891607, 4648786414414347,86363450200625247, 1693336666564186012] |