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) |
|---|---|
| 1 | 4 |
| 2 | 9 |
| 3 | 9 |
| 4 | 49 |
| 5 | 225 |
| 6 | 961 |
| 7 | 3969 |
| 8 | 16129 |
| 9 | 65025 |
| 10 | 261121 |
| 11 | 1046529 |
| 12 | 4190209 |
| 13 | 16769025 |
| 14 | 67092481 |
| 15 | 268402689 |
| 16 | 1073676289 |
| 17 | 4294836225 |
| 18 | 17179607041 |
| 19 | 68718952449 |
| 20 | 274876858369 |
| 21 | 1099509530625 |
| 22 | 4398042316801 |
| 23 | 17592177655809 |