| n | a(n) |
|---|---|
| 1 | 5 |
| 2 | 8 |
| 3 | 36 |
| 4 | 108 |
| 5 | 1440 |
| 6 | 5400 |
| 7 | 90720 |
| 8 | 423360 |
| 9 | 3144960 |
| 10 | 108864000 |
| 11 | 452390400 |
| 12 | 9340531200 |
| 13 | 261534873600 |
| 14 | 1961511552000 |
| 15 | 21794572800000 |
| 16 | 390558744576000 |
| 17 | 21341245685760000 |
| 18 | 136583972388864000 |
| 19 | 4196755964104704000 |
| 20 | 175168944588718080000 |
[5,8,36,108,1440,5400,90720,423360,3144960, 108864000,452390400,9340531200,261534873600, 1961511552000,21794572800000,390558744576000, 21341245685760000,136583972388864000, 4196755964104704000,175168944588718080000] |