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 | 47 |
| 5 | 219 |
| 6 | 1083 |
| 7 | 5597 |
| 8 | 29933 |
| 9 | 164547 |
| 10 | 925289 |
| 11 | 5303409 |
| 12 | 30898069 |
| 13 | 182587159 |
| 14 | 1092498017 |
| 15 | 6609496707 |
| 16 | 40383429717 |
| 17 | 248940496629 |
| 18 | 1546962207417 |
| 19 | 9683696676693 |
| 20 | 61024927547241 |
| 21 | 386936560902269 |
| 22 | 2467341175475253 |