n | a(n) |
---|---|
0 | 1 |
1 | 2 |
2 | 6 |
3 | 20 |
4 | 78 |
5 | 332 |
6 | 1516 |
7 | 7240 |
8 | 35734 |
9 | 180620 |
10 | 929940 |
11 | 4858328 |
12 | 25687052 |
13 | 137177016 |
14 | 738819672 |
15 | 4008435984 |
16 | 21886788582 |
17 | 120178329740 |
18 | 663179894788 |
19 | 3675923244856 |
20 | 20456707469540 |
21 | 114254175491304 |
22 | 640223315385576 |
[1,2,6,20,78,332,1516,7240,35734,180620,929940, 4858328,25687052,137177016,738819672,4008435984, 21886788582,120178329740,663179894788, 3675923244856,20456707469540,114254175491304, 640223315385576] |