n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 5 |
3 | 20 |
4 | 85 |
5 | 400 |
6 | 2046 |
7 | 11226 |
8 | 65676 |
9 | 407787 |
10 | 2675410 |
11 | 18475311 |
12 | 133843405 |
13 | 1014271763 |
14 | 8019687099 |
15 | 66011609670 |
16 | 564494701167 |
17 | 5005880952390 |
18 | 45958055208576 |
19 | 436161412834300 |
20 | 4273045478169842 |
21 | 43160044390231165 |
[1,1,5,20,85,400,2046,11226,65676,407787,2675410, 18475311,133843405,1014271763,8019687099, 66011609670,564494701167,5005880952390, 45958055208576,436161412834300,4273045478169842, 43160044390231165] |