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 | 0 |
| 2 | 4 |
| 3 | 36 |
| 4 | 1936 |
| 5 | 144260 |
| 6 | 31972988 |
| 7 | 6800311204 |
| 8 | 2560967581304 |
| 9 | 975834087080060 |
| 10 | 557171087172087364 |