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 | 3 |
| 3 | 23 |
| 4 | 201 |
| 5 | 2401 |
| 6 | 33723 |
| 7 | 564983 |
| 8 | 10832721 |
| 9 | 235620481 |
| 10 | 5715989043 |
| 11 | 153231400343 |
| 12 | 4495861836441 |
| 13 | 143343873560161 |
| 14 | 4934418832685163 |
| 15 | 182409363179578103 |
| 16 | 7206898465033427361 |
| 17 | 303073359560984509441 |
| 18 | 13516205633151976330083 |
| 19 | 637174194752117499594263 |