n | a(n) |
---|---|
0 | 1 |
1 | 4 |
2 | 18 |
3 | 85 |
4 | 410 |
5 | 1999 |
6 | 9807 |
7 | 48304 |
8 | 238570 |
9 | 1180615 |
10 | 5851253 |
11 | 29033074 |
12 | 144190943 |
13 | 716652070 |
14 | 3564079250 |
15 | 17734184365 |
16 | 88280673770 |
17 | 439625873215 |
18 | 2189988826125 |
19 | 10912480440850 |
20 | 54389237971285 |
21 | 271142650382080 |
[1,4,18,85,410,1999,9807,48304,238570,1180615, 5851253,29033074,144190943,716652070,3564079250, 17734184365,88280673770,439625873215, 2189988826125,10912480440850,54389237971285, 271142650382080] |