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 | 7 |
| 2 | 515 |
| 3 | 73211 |
| 4 | 2249220471 |
| 5 | 431283926958 |
| 6 | 18838905762720934 |
| 7 | 896134321804401371660 |
| 8 | 2333852111980919691995847581921 |
| 9 | 537961368577436933017494169487235 |