n | a(n) |
---|---|
1 | 4 |
2 | 12 |
3 | 24 |
4 | 72 |
5 | 120 |
6 | 408 |
7 | 840 |
8 | 2448 |
9 | 5760 |
10 | 15960 |
11 | 39864 |
12 | 108024 |
13 | 275184 |
14 | 728784 |
15 | 1895760 |
16 | 4998528 |
17 | 13033560 |
18 | 34250904 |
19 | 89602632 |
20 | 235157640 |
21 | 615871032 |
[4,12,24,72,120,408,840,2448,5760,15960,39864, 108024,275184,728784,1895760,4998528,13033560, 34250904,89602632,235157640,615871032] |