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 | 258 |
| 4 | 10830 |
| 5 | 709351 |
| 6 | 99699033 |
| 7 | 34719687359 |
| 8 | 32128580602967 |
| 9 | 82102610820820733 |
| 10 | 593301237469990370097 |