This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 6 | 81 |
| 7 | 561 |
| 8 | 4481 |
| 9 | 40321 |
| 10 | 403201 |
| 11 | 4435201 |
| 12 | 53222401 |
| 13 | 691891201 |
| 14 | 9686476801 |
| 15 | 145297152001 |
| 16 | 2324754432001 |
| 17 | 39520825344001 |
| 18 | 711374856192001 |
| 19 | 13516122267648001 |
| 20 | 270322445352960001 |
| 21 | 5676771352412160001 |