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 | 4 |
| 3 | 3189 |
| 4 | 178937854 |
| 5 | 2483527282663335 |
| 6 | 14325590003288422852078277 |
| 7 | 50976900301814584087291456618542388746 |