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 | 3 |
| 2 | 85 |
| 3 | 4536 |
| 4 | 357423 |
| 5 | 37312275 |
| 6 | 4853222764 |
| 7 | 756111184500 |
| 8 | 137272511800831 |
| 9 | 28460103232088385 |
| 10 | 6634460278534540725 |
| 11 | 1717750737160208150400 |
| 12 | 489078062391738506912340 |
| 13 | 151874660255802127280374140 |
| 14 | 51082995429153110239690350120 |
| 15 | 18500755859447038660174079965500 |