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 | 155 |
| 5 | 2685 |
| 6 | 65517 |
| 7 | 2063205 |
| 8 | 79715229 |
| 9 | 3653521179 |
| 10 | 193876702019 |
| 11 | 11696128639195 |
| 12 | 790788563411431 |
| 13 | 59238930606369007 |
| 14 | 4870881096635599567 |
| 15 | 436176889680415116607 |
| 16 | 42256722956163045301807 |
| 17 | 4403938204071514872757477 |
| 18 | 491317594015782152377769725 |
| 19 | 58423874601431980415156917525 |