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 | 1 |
| 3 | 2 |
| 4 | 3 |
| 5 | 8 |
| 6 | 19 |
| 7 | 76 |
| 8 | 263 |
| 9 | 1584 |
| 10 | 8199 |
| 11 | 73272 |
| 12 | 566401 |
| 13 | 7555072 |
| 14 | 87000289 |
| 15 | 1730799376 |
| 16 | 29728075177 |
| 17 | 881736342784 |
| 18 | 22583659690665 |
| 19 | 998900331837728 |
| 20 | 38149790451459859 |
| 21 | 2516220411436892160 |
| 22 | 143302702816187031875 |