n | a(n) |
---|---|
1 | 4 |
2 | 20 |
3 | 116 |
4 | 676 |
5 | 3940 |
6 | 22964 |
7 | 133844 |
8 | 780100 |
9 | 4546756 |
10 | 26500436 |
11 | 154455860 |
12 | 900234724 |
13 | 5246952484 |
14 | 30581480180 |
15 | 178241928596 |
16 | 1038870091396 |
17 | 6054978619780 |
18 | 35291001627284 |
19 | 205691031143924 |
20 | 1198855185236260 |
[4,20,116,676,3940,22964,133844,780100,4546756, 26500436,154455860,900234724,5246952484, 30581480180,178241928596,1038870091396, 6054978619780,35291001627284,205691031143924, 1198855185236260] |