n | a(n) |
---|---|
8 | 1 |
9 | 18 |
10 | 210 |
11 | 1980 |
12 | 16467 |
13 | 126126 |
14 | 912338 |
15 | 6332055 |
16 | 42615547 |
17 | 280182355 |
18 | 1809148533 |
19 | 11517941151 |
20 | 72515126734 |
21 | 452500330899 |
22 | 2803547693199 |
23 | 17270035728605 |
24 | 105888136423278 |
25 | 646765377652715 |
26 | 3938163632325325 |
27 | 23918395342393710 |
28 | 144963673674486886 |
[1,18,210,1980,16467,126126,912338,6332055, 42615547,280182355,1809148533,11517941151, 72515126734,452500330899,2803547693199, 17270035728605,105888136423278,646765377652715, 3938163632325325,23918395342393710, 144963673674486886] |