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 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 29 |
| 5 | 90 |
| 6 | 285 |
| 7 | 909 |
| 8 | 2984 |
| 9 | 9935 |
| 10 | 34113 |
| 11 | 119368 |
| 12 | 428923 |
| 13 | 1574223 |
| 14 | 5915235 |
| 15 | 22699730 |
| 16 | 89000042 |
| 17 | 356058539 |
| 18 | 1453069854 |
| 19 | 6044132793 |
| 20 | 25612564200 |
| 21 | 110503626702 |
| 22 | 485161228675 |
| 23 | 2166488899641 |
| 24 | 9835209480533 |
| 25 | 45370059225227 |