n | a(n) |
---|---|
0 | 1 |
1 | 4 |
2 | 30 |
3 | 280 |
4 | 2890 |
5 | 31584 |
6 | 358176 |
7 | 4168560 |
8 | 49455450 |
9 | 595480600 |
10 | 7254787540 |
11 | 89234708160 |
12 | 1106335812400 |
13 | 13808393670400 |
14 | 173332340911200 |
15 | 2186551157230560 |
16 | 27701981424940890 |
17 | 352297514508697800 |
18 | 4495418315974868700 |
19 | 57535568476437651600 |
20 | 738373616359119126540 |
[1,4,30,280,2890,31584,358176,4168560,49455450, 595480600,7254787540,89234708160,1106335812400, 13808393670400,173332340911200,2186551157230560, 27701981424940890,352297514508697800, 4495418315974868700,57535568476437651600, 738373616359119126540] |