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 | 5 |
| 3 | 23 |
| 4 | 83 |
| 5 | 299 |
| 6 | 1081 |
| 7 | 3931 |
| 8 | 14293 |
| 9 | 51955 |
| 10 | 188859 |
| 11 | 686519 |
| 12 | 2495537 |
| 13 | 9071325 |
| 14 | 32974351 |
| 15 | 119862177 |
| 16 | 435700975 |
| 17 | 1583780905 |
| 18 | 5757072535 |
| 19 | 20927062737 |
| 20 | 76070247573 |
| 21 | 276516705575 |
| 22 | 1005143149813 |
| 23 | 3653713262601 |
| 24 | 13281312856865 |