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 | 2 |
| 2 | 6 |
| 3 | 15 |
| 4 | 41 |
| 5 | 106 |
| 6 | 284 |
| 7 | 750 |
| 8 | 2010 |
| 9 | 5382 |
| 10 | 14523 |
| 11 | 39290 |
| 12 | 106854 |
| 13 | 291552 |
| 14 | 798675 |
| 15 | 2194828 |
| 16 | 6051153 |
| 17 | 16730373 |
| 18 | 46383002 |
| 19 | 128910484 |
| 20 | 359115067 |
| 21 | 1002575810 |
| 22 | 2804667061 |
| 23 | 7860780578 |
| 24 | 22070885735 |
| 25 | 62071872704 |
| 26 | 174842835886 |
| 27 | 493217417610 |