n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 1 |
3 | 2 |
4 | 6 |
5 | 19 |
6 | 80 |
7 | 395 |
8 | 2487 |
9 | 19890 |
10 | 206565 |
11 | 2804453 |
12 | 49872647 |
13 | 1158843214 |
14 | 35049606566 |
15 | 1374685228988 |
16 | 69690886873398 |
17 | 4554367168841547 |
[0,0,1,2,6,19,80,395,2487,19890,206565,2804453, 49872647,1158843214,35049606566,1374685228988, 69690886873398,4554367168841547] |