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 | 3 |
| 2 | 9 |
| 3 | 25 |
| 4 | 69 |
| 5 | 189 |
| 6 | 517 |
| 7 | 1413 |
| 8 | 3861 |
| 9 | 10549 |
| 10 | 28821 |
| 11 | 78741 |
| 12 | 215125 |
| 13 | 587733 |
| 14 | 1605717 |
| 15 | 4386901 |
| 16 | 11985237 |
| 17 | 32744277 |
| 18 | 89459029 |
| 19 | 244406613 |
| 20 | 667731285 |
| 21 | 1824275797 |
| 22 | 4984014165 |
| 23 | 13616579925 |
| 24 | 37201188181 |
| 25 | 101635536213 |
| 26 | 277673448789 |
| 27 | 758617970005 |
| 28 | 2072582837589 |
| 29 | 5662401615189 |