n | a(n) |
---|---|
1 | 4 |
2 | 20 |
3 | 60 |
4 | 358 |
5 | 1626 |
6 | 7232 |
7 | 34717 |
8 | 160988 |
9 | 748843 |
10 | 3514426 |
11 | 16448990 |
12 | 76889286 |
13 | 359867470 |
14 | 1684122959 |
15 | 7879951514 |
16 | 36879246800 |
17 | 172597946528 |
18 | 807735845097 |
19 | 3780221117751 |
20 | 17691605965676 |
21 | 82797291928191 |
22 | 387496301051514 |
[4,20,60,358,1626,7232,34717,160988,748843, 3514426,16448990,76889286,359867470,1684122959, 7879951514,36879246800,172597946528,807735845097, 3780221117751,17691605965676,82797291928191, 387496301051514] |