n | a(n) |
---|---|
1 | 0 |
2 | 1 |
3 | 2 |
4 | 7 |
5 | 28 |
6 | 124 |
7 | 588 |
8 | 2939 |
9 | 15292 |
10 | 82168 |
11 | 453376 |
12 | 2558074 |
13 | 14712038 |
14 | 86029132 |
15 | 510455002 |
16 | 3068304865 |
17 | 18658787150 |
18 | 114663168405 |
19 | 711391109162 |
20 | 4452321247688 |
21 | 28090360338572 |
22 | 178550339417087 |
23 | 1142799275636690 |
[0,1,2,7,28,124,588,2939,15292,82168,453376, 2558074,14712038,86029132,510455002,3068304865, 18658787150,114663168405,711391109162, 4452321247688,28090360338572,178550339417087, 1142799275636690] |