n | a(n) |
---|---|
1 | 0 |
2 | 1 |
3 | 2 |
4 | 8 |
5 | 25 |
6 | 77 |
7 | 236 |
8 | 721 |
9 | 2198 |
10 | 6698 |
11 | 20408 |
12 | 62173 |
13 | 189414 |
14 | 577055 |
15 | 1758012 |
16 | 5355828 |
17 | 16316664 |
18 | 49709120 |
19 | 151440064 |
20 | 461365896 |
21 | 1405562597 |
22 | 4282081163 |
23 | 13045466011 |
24 | 39743334364 |
25 | 121079049617 |
26 | 168870314746 |
[0,1,2,8,25,77,236,721,2198,6698,20408,62173, 189414,577055,1758012,5355828,16316664,49709120, 151440064,461365896,1405562597,4282081163, 13045466011,39743334364,121079049617,168870314746] |