n | a(n) |
---|---|
0 | 1 |
1 | 2 |
2 | 4 |
3 | 10 |
4 | 32 |
5 | 130 |
6 | 640 |
7 | 3770 |
8 | 25600 |
9 | 199810 |
10 | 1740800 |
11 | 16983850 |
12 | 181043200 |
13 | 2122981250 |
14 | 26794393600 |
15 | 367275756250 |
16 | 5358878720000 |
17 | 84106148181250 |
18 | 1393308467200000 |
19 | 24643101417106250 |
20 | 457005177241600000 |
[1,2,4,10,32,130,640,3770,25600,199810,1740800, 16983850,181043200,2122981250,26794393600, 367275756250,5358878720000,84106148181250, 1393308467200000,24643101417106250, 457005177241600000] |