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 | 0 |
| 1 | 1 |
| 2 | 78 |
| 3 | 20487601 |
| 4 | 369071811667060977001038 |
| 5 | 2157596228176369025492751451130809592490957353466093604326704974092869041 |