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 | 42 |
| 4 | 453 |
| 5 | 5651 |
| 6 | 77498 |
| 7 | 1135828 |
| 8 | 17485309 |
| 9 | 279540684 |