n | a(n) |
---|---|
1 | 1 |
2 | 1 |
3 | 2 |
4 | 4 |
5 | 12 |
6 | 40 |
7 | 153 |
8 | 638 |
9 | 2825 |
10 | 12938 |
11 | 60458 |
12 | 285664 |
13 | 1358283 |
14 | 6480694 |
15 | 30979999 |
16 | 148249768 |
17 | 709832688 |
18 | 3399805736 |
19 | 16286469156 |
20 | 78026226228 |
21 | 373832145200 |
22 | 1791120945112 |
[1,1,2,4,12,40,153,638,2825,12938,60458,285664, 1358283,6480694,30979999,148249768,709832688, 3399805736,16286469156,78026226228,373832145200, 1791120945112] |