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 | 1 |
| 2 | 3 |
| 3 | 11 |
| 4 | 43 |
| 5 | 187 |
| 6 | 872 |
| 7 | 4375 |
| 8 | 23258 |
| 9 | 130485 |
| 10 | 767348 |
| 11 | 4710715 |
| 12 | 30070205 |
| 13 | 198983975 |
| 14 | 1361361925 |
| 15 | 9607908808 |
| 16 | 69812787049 |
| 17 | 521377973359 |
| 18 | 3996036977270 |
| 19 | 31389624598631 |
| 20 | 252408597286705 |
| 21 | 2075472033455894 |
| 22 | 17434190966525003 |
| 23 | 149476993511444023 |
| 24 | 1307022313790487959 |