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 | 2 |
| 3 | 3 |
| 4 | 7 |
| 5 | 12 |
| 6 | 42 |
| 7 | 123 |
| 8 | 503 |
| 9 | 2008 |
| 10 | 8720 |
| 11 | 38365 |
| 12 | 173609 |
| 13 | 792828 |
| 14 | 3662924 |
| 15 | 17034381 |
| 16 | 79703081 |
| 17 | 374624254 |
| 18 | 1767883444 |
| 19 | 8370666417 |
| 20 | 39751072847 |
| 21 | 189262621864 |
| 22 | 903220058756 |
| 23 | 4319518316899 |
| 24 | 20697040198889 |
| 25 | 99343899144822 |
| 26 | 477609477924308 |
| 27 | 2299585449279713 |