n | a(n) |
---|---|
1 | 4 |
2 | 28 |
3 | 181 |
4 | 1180 |
5 | 7687 |
6 | 50077 |
7 | 326233 |
8 | 2125270 |
9 | 13845268 |
10 | 90196219 |
11 | 587591326 |
12 | 3827916001 |
13 | 24937299865 |
14 | 162456261409 |
15 | 1058335787620 |
16 | 6894622770400 |
17 | 44915634248581 |
18 | 292606900638904 |
19 | 1906213721217931 |
20 | 12418199102692513 |
[4,28,181,1180,7687,50077,326233,2125270,13845268, 90196219,587591326,3827916001,24937299865, 162456261409,1058335787620,6894622770400, 44915634248581,292606900638904,1906213721217931, 12418199102692513] |