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 | 51 |
| 4 | 18731 |
| 5 | 408990251 |
| 6 | 921132763911411 |
| 7 | 324499299994016295527283 |
| 8 | 25190248259800264134073495741338539 |
| 9 | 576797123806621878513443912437627670334052360619 |