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 | 6 |
| 3 | 26 |
| 4 | 100 |
| 5 | 363 |
| 6 | 1274 |
| 7 | 4372 |
| 8 | 14760 |
| 9 | 49205 |
| 10 | 162382 |
| 11 | 531438 |
| 12 | 1727180 |
| 13 | 5580127 |
| 14 | 17936130 |
| 15 | 57395624 |
| 16 | 182948560 |
| 17 | 581130729 |
| 18 | 1840247318 |
| 19 | 5811307330 |
| 20 | 18305618100 |
| 21 | 57531942611 |
| 22 | 180441092746 |
| 23 | 564859072956 |
| 24 | 1765184603000 |
| 25 | 5507375961373 |
| 26 | 17157594341214 |
| 27 | 53379182394902 |