n | a(n) |
---|---|
1 | 1 |
2 | 4 |
3 | 20 |
4 | 110 |
5 | 636 |
6 | 3790 |
7 | 23036 |
8 | 141946 |
9 | 883360 |
10 | 5538098 |
11 | 34917224 |
12 | 221125102 |
13 | 1405276324 |
14 | 8956020294 |
15 | 57209977908 |
16 | 366147270370 |
17 | 2347081505816 |
18 | 15065301857194 |
19 | 96808851937152 |
20 | 622682497349910 |
21 | 4008412023724124 |
22 | 25821543284366686 |
23 | 166438749582676204 |
[1,4,20,110,636,3790,23036,141946,883360,5538098, 34917224,221125102,1405276324,8956020294, 57209977908,366147270370,2347081505816, 15065301857194,96808851937152,622682497349910, 4008412023724124,25821543284366686, 166438749582676204] |