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 | 3 |
| 2 | 7 |
| 3 | 31 |
| 4 | 201 |
| 5 | 1713 |
| 6 | 18075 |
| 7 | 227295 |
| 8 | 3317265 |
| 9 | 55103265 |
| 10 | 1026318195 |
| 11 | 21181092975 |
| 12 | 479733356025 |
| 13 | 11829834687825 |
| 14 | 315481555464075 |
| 15 | 9046941599670975 |
| 16 | 277598531343758625 |
| 17 | 9075051786962786625 |
| 18 | 314884420627497595875 |
| 19 | 11557482238066613223375 |
| 20 | 447385119579169194047625 |