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 | 7 |
| 2 | 55 |
| 3 | 433 |
| 4 | 3409 |
| 5 | 26839 |
| 6 | 211303 |
| 7 | 1663585 |
| 8 | 13097377 |
| 9 | 103115431 |
| 10 | 811826071 |
| 11 | 6391493137 |
| 12 | 50320119025 |
| 13 | 396169459063 |
| 14 | 3119035553479 |
| 15 | 24556114968769 |
| 16 | 193329884196673 |
| 17 | 1522082958604615 |
| 18 | 11983333784640247 |
| 19 | 94344587318517361 |