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 | 5 |
| 3 | 18 |
| 4 | 68 |
| 5 | 239 |
| 6 | 845 |
| 7 | 2958 |
| 8 | 10349 |
| 9 | 36111 |
| 10 | 126121 |
| 11 | 441161 |
| 12 | 1546353 |
| 13 | 5432430 |
| 14 | 19130949 |
| 15 | 67536934 |
| 16 | 238991556 |
| 17 | 847646318 |
| 18 | 3012890719 |
| 19 | 10730694626 |
| 20 | 38289978058 |
| 21 | 136865206035 |
| 22 | 489995352710 |
| 23 | 1756812943841 |
| 24 | 6307268945198 |