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 | 0 |
| 2 | 1 |
| 3 | 5 |
| 4 | 55 |
| 5 | 1346269 |
| 6 | 9227465 |
| 7 | 4052739537881 |
| 8 | 498454011879264 |
| 9 | 1672445759041379840132227567949787325 |
| 10 | 18547707689471986212190138521399707760 |
| 11 | 619220451666590135228675387863297874269396512 |