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 | 1 |
| 3 | 5 |
| 4 | 35 |
| 5 | 297 |
| 6 | 2873 |
| 7 | 30657 |
| 8 | 353727 |
| 9 | 4355497 |
| 10 | 56709337 |
| 11 | 775575269 |
| 12 | 11085971235 |
| 13 | 164979882033 |
| 14 | 2548461481105 |
| 15 | 40762085472929 |
| 16 | 673751263927071 |
| 17 | 11489101983573105 |
| 18 | 201838769635965969 |
| 19 | 3648620371959258149 |
| 20 | 67795012307507004291 |
| 21 | 1293607920940368319641 |
| 22 | 25326486746707799668105 |
| 23 | 508368313083167614599201 |
| 24 | 10454499119633293760277151 |
| 25 | 220120546753823908307191769 |
| 26 | 4742197866143368618862457641 |