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) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 15 |
| 4 | 75 |
| 5 | 6308237 |
| 6 | 871506915 |
| 7 | 2465425275 |
| 8 | 2937864075 |
| 9 | 2948967789 |
| 10 | 83313712623 |
| 11 | 195392257275 |
| 12 | 11126651718075 |
| 13 | 45237726869109 |
| 14 | 2920008144904215 |