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) |
|---|---|
| 3 | 2 |
| 4 | 6 |
| 5 | 22 |
| 6 | 102 |
| 7 | 582 |
| 8 | 3942 |
| 9 | 30822 |
| 10 | 272742 |
| 11 | 2691942 |
| 12 | 29303142 |
| 13 | 348637542 |
| 14 | 4499984742 |
| 15 | 62618845542 |
| 16 | 934401757542 |
| 17 | 14882928349542 |
| 18 | 252007880413542 |
| 19 | 4520257017565542 |
| 20 | 85616990623453542 |
| 21 | 1707551662741213542 |
| 22 | 35768179777214173542 |
| 23 | 785101998295619293542 |
| 24 | 18019779824218937053542 |