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 | 9 |
| 2 | 81 |
| 3 | 221 |
| 4 | 575 |
| 5 | 1673 |
| 6 | 4881 |
| 7 | 14825 |
| 8 | 45411 |
| 9 | 141381 |
| 10 | 443159 |
| 11 | 1399925 |
| 12 | 4442717 |
| 13 | 14159449 |
| 14 | 45263327 |
| 15 | 145061281 |
| 16 | 465794335 |
| 17 | 1498036809 |
| 18 | 4823779033 |
| 19 | 15548389529 |
| 20 | 50156459339 |
| 21 | 161898944109 |
| 22 | 522854621863 |
| 23 | 1689250105197 |
| 24 | 5459434154405 |