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 | 12870 |
| 3 | 9465511770 |
| 4 | 580132098966420 |
| 5 | 19840440079542390102 |
| 6 | 1061489454895820193068774 |