n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 3 |
3 | 7 |
4 | 20 |
5 | 54 |
6 | 164 |
7 | 500 |
8 | 1630 |
9 | 5472 |
10 | 19257 |
11 | 70133 |
12 | 265858 |
13 | 1042346 |
14 | 4235031 |
15 | 17760943 |
16 | 76913277 |
17 | 342919431 |
18 | 1573637985 |
19 | 7415371293 |
20 | 35860511131 |
21 | 177641956111 |
22 | 900782461170 |
23 | 4668600610346 |
24 | 24714284921937 |
25 | 133467868645017 |
26 | 734844788634269 |
27 | 4120752558254581 |
[1,1,3,7,20,54,164,500,1630,5472,19257,70133, 265858,1042346,4235031,17760943,76913277, 342919431,1573637985,7415371293,35860511131, 177641956111,900782461170,4668600610346, 24714284921937,133467868645017,734844788634269, 4120752558254581] |