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 | 1 |
| 2 | 2 |
| 3 | 7 |
| 4 | 47 |
| 5 | 513 |
| 6 | 8020 |
| 7 | 169227 |
| 8 | 4637965 |
| 9 | 159568981 |
| 10 | 6684686230 |
| 11 | 332681461871 |
| 12 | 19316990453131 |
| 13 | 1292074091000105 |
| 14 | 98636639620170792 |
| 15 | 8528989125071254867 |
| 16 | 829516920337723299465 |
| 17 | 90124512307642049807293 |
| 18 | 10865612430780251465538154 |