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 | 193 |
| 4 | 611 |
| 5 | 1602 |
| 6 | 3513 |
| 7 | 8327 |
| 8 | 17568 |
| 9 | 36988 |
| 10 | 76723 |
| 11 | 153865 |
| 12 | 308777 |
| 13 | 608391 |
| 14 | 1189918 |
| 15 | 2313136 |
| 16 | 4458599 |
| 17 | 8562580 |
| 18 | 16354499 |
| 19 | 31118601 |
| 20 | 59018399 |
| 21 | 111556847 |
| 22 | 210352934 |
| 23 | 395641010 |
| 24 | 742567333 |
| 25 | 1391072247 |
| 26 | 2601239676 |
| 27 | 4856734666 |