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 | 4 |
| 2 | 14 |
| 3 | 53 |
| 4 | 195 |
| 5 | 711 |
| 6 | 2662 |
| 7 | 9973 |
| 8 | 37367 |
| 9 | 141472 |
| 10 | 537422 |
| 11 | 2045224 |
| 12 | 7821958 |
| 13 | 30001955 |
| 14 | 115296650 |
| 15 | 444336395 |
| 16 | 1716137440 |
| 17 | 6639137474 |
| 18 | 25732460158 |
| 19 | 99897347527 |
| 20 | 388339939659 |
| 21 | 1511670332538 |
| 22 | 5891647475819 |
| 23 | 22987227251180 |