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) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 9 |
| 4 | 25 |
| 5 | 81 |
| 6 | 289 |
| 7 | 961 |
| 8 | 3249 |
| 9 | 11025 |
| 10 | 37249 |
| 11 | 126025 |
| 12 | 426409 |
| 13 | 1442401 |
| 14 | 4879681 |
| 15 | 16507969 |
| 16 | 55845729 |
| 17 | 188925025 |
| 18 | 639128961 |
| 19 | 2162157001 |
| 20 | 7314525625 |
| 21 | 24744863025 |
| 22 | 83711270241 |
| 23 | 283193201281 |
| 24 | 958035736849 |
| 25 | 3241011678961 |