| n | a(n) |
|---|---|
| 1 | 64 |
| 2 | 21 |
| 3 | 1065 |
| 4 | 172 |
| 5 | 6423 |
| 6 | 8756 |
| 7 | 55922 |
| 8 | 465040 |
| 9 | 1136003 |
| 10 | 19265064 |
| 11 | 60547641 |
| 12 | 699553699 |
| 13 | 3796928584 |
| 14 | 26139308319 |
| 15 | 214325335931 |
| 16 | 1151196050162 |
| 17 | 10992872734396 |
| 18 | 60033419186727 |
| 19 | 538343914163895 |
| 20 | 3376563558675197 |
[64,21,1065,172,6423,8756,55922,465040,1136003, 19265064,60547641,699553699,3796928584, 26139308319,214325335931,1151196050162, 10992872734396,60033419186727,538343914163895, 3376563558675197] |