n | a(n) |
---|---|
0 | 1 |
1 | 20 |
2 | 230 |
3 | 1960 |
4 | 13685 |
5 | 82524 |
6 | 443870 |
7 | 2175800 |
8 | 9869990 |
9 | 41907380 |
10 | 168012824 |
11 | 640438680 |
12 | 2334121995 |
13 | 8171039800 |
14 | 27580783270 |
15 | 90058003200 |
16 | 285253928790 |
17 | 878572253720 |
18 | 2636748302650 |
19 | 7725084195240 |
20 | 22130265931900 |
21 | 62079251390180 |
[1,20,230,1960,13685,82524,443870,2175800,9869990, 41907380,168012824,640438680,2334121995, 8171039800,27580783270,90058003200,285253928790, 878572253720,2636748302650,7725084195240, 22130265931900,62079251390180] |