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 | 2 |
| 3 | 6 |
| 4 | 42 |
| 5 | 798 |
| 6 | 42294 |
| 7 | 5540514 |
| 8 | 1723099854 |
| 9 | 1238908795026 |
| 10 | 2005793339147094 |
| 11 | 7363267348008982074 |
| 12 | 60091624827101302705914 |
| 13 | 1073416694286510570235741782 |
| 14 | 41726927156999525396773990291686 |
| 15 | 3505771238949629125260760342336582662 |