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 | 2 |
| 1 | 20 |
| 2 | 402 |
| 3 | 14440 |
| 4 | 825502 |
| 5 | 69055260 |
| 6 | 7960285802 |
| 7 | 1209873973712 |