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 | 15 |
| 2 | 497 |
| 3 | 22031 |
| 4 | 1124849 |
| 5 | 62379535 |
| 6 | 3651676657 |
| 7 | 222085764623 |
| 8 | 13895337519601 |
| 9 | 888654458770959 |
| 10 | 57831897893972465 |
| 11 | 3817410543738148367 |
| 12 | 254970980461934291441 |
| 13 | 17200148833928765494799 |